diff --git a/src/CLASS/D17/swea/prob1238_contact.java b/src/CLASS/D17/swea/prob1238_contact.java
new file mode 100644
index 0000000..1059987
--- /dev/null
+++ b/src/CLASS/D17/swea/prob1238_contact.java
@@ -0,0 +1,79 @@
+package CLASS.D17.swea;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Queue;
+import java.util.StringTokenizer;
+
+
+public class prob1238_contact {
+
+    static int n;
+    static ArrayList<Integer> arr[]=new ArrayList[101];
+    public static void main(String[] args) throws IOException {
+        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st;
+        StringBuilder sb= new StringBuilder();
+
+        //int t=Integer.parseInt(in.readLine());
+        int t=10;
+        int tt=0;
+        for (int i = 0; i < 101; i++) {
+            arr[i]=new ArrayList<>();
+        }
+        while(t>tt){
+            st = new StringTokenizer(in.readLine(), " ");
+            n=Integer.parseInt(st.nextToken());
+            int s=Integer.parseInt(st.nextToken());
+
+            setArr();
+            sb.append("#").append(++tt).append(" ");
+            st=new StringTokenizer(in.readLine()," ");
+            for (int i = 0; i < n/2; i++) {
+                int val1=Integer.parseInt(st.nextToken());
+                int val2=Integer.parseInt(st.nextToken());
+                arr[val1].add(val2);
+            }
+
+           sb.append(BFS(s)).append("\n");
+        }
+        System.out.println(sb);
+    }
+
+    private static int BFS(int s) {
+        Queue<Integer> q= new ArrayDeque<>();
+        int depth[]=new int[101];
+        q.offer(s);
+        while(!q.isEmpty()){
+            int node= q.poll();
+            for (int i = 0; i < arr[node].size(); i++) {
+                int cnode=arr[node].get(i);
+                if(depth[cnode]==0&&cnode!=s){
+                    depth[cnode]=depth[node]+1;
+                    q.offer(cnode);
+                }
+            }
+        }
+        int mdepth=0,val=0;
+        for (int i = 1; i < 101; i++) {
+            if(mdepth<depth[i]){
+                mdepth=depth[i];
+                val=i;
+            }
+            else if(mdepth==depth[i]){
+                val=i;
+            }
+        }
+        return val;
+    }
+
+    private static void setArr() {
+        for (int i = 1; i < 101; i++) {
+            arr[i].clear();
+        }
+    }
+
+}
\ No newline at end of file
diff --git "a/src/CLASS/D18/boj/prob17143_\353\202\232\354\213\234\354\231\225.java" "b/src/CLASS/D18/boj/prob17143_\353\202\232\354\213\234\354\231\225.java"
new file mode 100644
index 0000000..f706546
--- /dev/null
+++ "b/src/CLASS/D18/boj/prob17143_\353\202\232\354\213\234\354\231\225.java"
@@ -0,0 +1,133 @@
+package CLASS.D18.boj;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.StringTokenizer;
+
+
+public class prob17143_낚시왕 {
+
+    static int r, c, m;
+    static int arr[][];
+    static int speed[];
+    static int direction[];
+    static int size[];
+    static boolean isMove[];
+    static List<int[]> shark = new ArrayList<>();
+
+    static int[] par;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st;
+        StringBuilder sb = new StringBuilder();
+
+        st = new StringTokenizer(in.readLine(), " ");
+        r = Integer.parseInt(st.nextToken());
+        c = Integer.parseInt(st.nextToken());
+        m = Integer.parseInt(st.nextToken());
+        arr = new int[r + 1][c + 1];
+
+        speed = new int[m + 1];
+        direction = new int[m + 1];
+        size = new int[m + 1];
+        isMove = new boolean[m + 1];
+
+        shark.add(null);
+        for (int i = 1; i <= m; i++) {
+            st = new StringTokenizer(in.readLine(), " ");
+            int x = Integer.parseInt(st.nextToken());
+            int y = Integer.parseInt(st.nextToken());
+
+            arr[x][y] = i;
+            shark.add(new int[]{x, y});
+            speed[i] = Integer.parseInt(st.nextToken());
+            direction[i] = Integer.parseInt(st.nextToken());
+            size[i] = Integer.parseInt(st.nextToken());
+        }
+        size[0] = 0;
+
+        int sum = 0;
+
+        for (int i = 1; i < c; i++) {
+            sum += getFish(i);
+            Arrays.fill(isMove, false);
+            for (int j = 1; j <= m; j++) {
+                if (shark.get(j) != null) {
+                    moveShark(j);
+                }
+            }
+        }
+        sum += getFish(c);
+
+        System.out.println(sum);
+    }
+
+    static int dx[] = {-1, 1, 0, 0};
+    static int dy[] = {0, 0, 1, -1};
+
+    private static void moveShark(int s) {
+        int len;
+        int mx = shark.get(s)[0];
+        int my = shark.get(s)[1];
+        if(!isMove[arr[mx][my]]){
+            arr[mx][my]=0;
+        }
+        if (direction[s] == 1 || direction[s] == 2) {
+            len = speed[s] % ((r - 1) * 2);
+            while (len > 0) {
+                if (mx == 1) {
+                    direction[s] = 2;
+                } else if (mx == r) {
+                    direction[s] = 1;
+                }
+                mx = mx + dx[direction[s] - 1];
+                len--;
+            }
+        } else {
+            len = speed[s] % ((c - 1) * 2);
+            while (len > 0) {
+                if (my == 1) {
+                    direction[s] = 3;
+
+                } else if (my == c) {
+                    direction[s] = 4;
+                }
+                my = my + dy[direction[s] - 1];
+                len--;
+            }
+        }
+
+        isMove[s] = true;
+
+        if (arr[mx][my] != 0 && isMove[arr[mx][my]]) {
+            if (size[arr[mx][my]] > size[s]) {
+                shark.set(s, null);
+            } else {
+                shark.set(arr[mx][my], null);
+                arr[mx][my] = s;
+                shark.set(s, new int[]{mx, my});
+            }
+        } else {
+            arr[mx][my] = s;
+            shark.set(s, new int[]{mx, my});
+        }
+    }
+
+    private static int getFish(int loc) {
+        for (int i = 1; i <= r; i++) {
+            if (arr[i][loc] != 0) {
+                int s = arr[i][loc];
+                arr[i][loc] = 0;
+                shark.set(s, null);
+                return size[s];
+            }
+        }
+        return 0;
+    }
+
+}
\ No newline at end of file
diff --git a/src/CLASS/D22/Memoization_sample.java b/src/CLASS/D22/Memoization_sample.java
new file mode 100644
index 0000000..b19f448
--- /dev/null
+++ b/src/CLASS/D22/Memoization_sample.java
@@ -0,0 +1,29 @@
+package CLASS.D22;
+
+import java.util.Arrays;
+import java.util.Scanner;
+
+public class Memoization_sample {
+
+    private static long[] memo;
+
+    private static long fibo2(int n) {
+        if (memo[n] == -1) {
+            memo[n] = fibo2(n - 1) + fibo2(n - 2);
+        }
+        return memo[n];
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int n = sc.nextInt();
+
+        memo = new long[n + 1];
+        Arrays.fill(memo, -1);
+        memo[0] = 0;
+        memo[1] = 1;
+
+        System.out.println(fibo2(n));
+
+    }
+}
diff --git "a/src/CLASS/D22/boj/prob1149_RGB\352\261\260\353\246\254.java" "b/src/CLASS/D22/boj/prob1149_RGB\352\261\260\353\246\254.java"
new file mode 100644
index 0000000..9b21e33
--- /dev/null
+++ "b/src/CLASS/D22/boj/prob1149_RGB\352\261\260\353\246\254.java"
@@ -0,0 +1,34 @@
+package CLASS.D22.boj;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class prob1149_RGB거리 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
+        int n=Integer.parseInt(in.readLine());
+        StringTokenizer st;
+        int home[][]=new int[n][3];
+        int dp[][]=new int[n][3];
+
+        for (int i = 0; i < n; i++) {
+            st=new StringTokenizer(in.readLine()," ");
+            home[i][0]=Integer.parseInt(st.nextToken());
+            home[i][1]=Integer.parseInt(st.nextToken());
+            home[i][2]=Integer.parseInt(st.nextToken());
+        }
+        dp[0][0]=home[0][0];
+        dp[0][1]=home[0][1];
+        dp[0][2]=home[0][2];
+
+        for (int i = 1; i < n; i++) {
+            dp[i][0]=home[i][0]+Math.min(dp[i-1][1],dp[i-1][2]);
+            dp[i][1]=home[i][1]+Math.min(dp[i-1][0],dp[i-1][2]);
+            dp[i][2]=home[i][2]+Math.min(dp[i-1][0],dp[i-1][1]);
+        }
+        System.out.println(Math.min(dp[n-1][0],Math.min(dp[n-1][1],dp[n-1][2])));
+
+    }
+}
diff --git "a/src/CLASS/D22/boj/prob1463_1\353\241\234\353\247\214\353\223\244\352\270\260.java" "b/src/CLASS/D22/boj/prob1463_1\353\241\234\353\247\214\353\223\244\352\270\260.java"
new file mode 100644
index 0000000..62e914e
--- /dev/null
+++ "b/src/CLASS/D22/boj/prob1463_1\353\241\234\353\247\214\353\223\244\352\270\260.java"
@@ -0,0 +1,35 @@
+package CLASS.D22.boj;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Arrays;
+import java.util.StringTokenizer;
+
+public class prob1463_1로만들기
+{
+    static int dp[];
+    static int n;
+    public static void main(String[] args) throws IOException {
+        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb= new StringBuilder();
+        StringTokenizer st;
+
+        n=Integer.parseInt(in.readLine());
+
+        dp=new int[n+1];
+        dp[1] = 0;
+
+        for (int i = 2; i < n + 1; i++) {
+            dp[i] = dp[i - 1] + 1;
+            if (i % 2 == 0 && dp[i] > dp[i / 2] + 1) {
+                dp[i] = dp[i / 2] + 1;
+            }
+            if (i % 3 == 0 && dp[i] > dp[i / 3] + 1) {
+                dp[i] = dp[i / 3] + 1;
+            }
+        }
+        System.out.println(dp[n]);
+    }
+
+}
diff --git "a/src/CLASS/D23/boj/prob1010_\353\213\244\353\246\254\353\206\223\352\270\260.java" "b/src/CLASS/D23/boj/prob1010_\353\213\244\353\246\254\353\206\223\352\270\260.java"
new file mode 100644
index 0000000..1c031b5
--- /dev/null
+++ "b/src/CLASS/D23/boj/prob1010_\353\213\244\353\246\254\353\206\223\352\270\260.java"
@@ -0,0 +1,51 @@
+package CLASS.D23.boj;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class prob1010_다리놓기 {
+
+    static int cnt;
+    public static void main(String[] args) throws IOException {
+        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
+
+        int t=Integer.parseInt(in.readLine());
+        int tt=0;
+
+        while(t>tt){
+            int n,m;
+            StringTokenizer st=new StringTokenizer(in.readLine()," ");
+            n=Integer.parseInt(st.nextToken());
+            m=Integer.parseInt(st.nextToken());
+
+            if(n>m){
+                calcComb(n, m);
+            }
+            else if(n<m){
+                int[][]b=new int[n+1][m+1];
+                calcComb(m, n);
+            }
+            else{
+                cnt=1;
+            }
+            System.out.println(cnt);
+            cnt=0;
+            tt++;
+        }
+    }
+
+    private static void calcComb(int n, int m) {
+        if(m>n-m) m=n-m;
+        int[][]b=new int[n+1][m+1];
+        for (int i = 0; i <=n; i++) {
+            for (int j = 0, end= Math.min(i,m);j<=end; j++) {
+                if(j==0||i==j)
+                    b[i][j]=1;
+                else b[i][j]=b[i-1][j-1]+b[i-1][j];
+            }
+        }
+        cnt=b[n][m];
+    }
+}
diff --git "a/src/CLASS/D23/boj/prob17070_\355\214\214\354\235\264\355\224\204\354\230\256\352\270\260\352\270\260.java" "b/src/CLASS/D23/boj/prob17070_\355\214\214\354\235\264\355\224\204\354\230\256\352\270\260\352\270\260.java"
new file mode 100644
index 0000000..6305c09
--- /dev/null
+++ "b/src/CLASS/D23/boj/prob17070_\355\214\214\354\235\264\355\224\204\354\230\256\352\270\260\352\270\260.java"
@@ -0,0 +1,56 @@
+package CLASS.D23.boj;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayDeque;
+import java.util.Arrays;
+import java.util.Queue;
+import java.util.StringTokenizer;
+
+public class prob17070_파이프옮기기 {
+
+    static int table[][];
+    static int dp[][][];
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st;
+        int n = Integer.parseInt(in.readLine());
+
+        table = new int[n][n];
+
+        dp = new int[n][n][3];
+
+
+        for (int i = 0; i < n; i++) {
+            st = new StringTokenizer(in.readLine(), " ");
+            for (int j = 0; j < n; j++) {
+
+                table[i][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+
+        dp[0][1][0] = 1;
+        for (int i = 0; i < n; i++) {
+            for (int j = 1; j < n; j++) {
+                if(table[i][j]==1){
+                    continue;
+                }
+                if (i == 0) {
+                    if(j<2) continue;
+                    dp[i][j][0] = dp[i][j - 1][0];
+                }
+                else{
+                    dp[i][j][0]=dp[i][j-1][0]+dp[i][j-1][1];
+                    dp[i][j][2]=dp[i-1][j][1]+dp[i-1][j][2];
+                    if((table[i-1][j]+ table[i][j-1])==0){
+                        dp[i][j][1]=dp[i-1][j-1][1]+dp[i-1][j-1][0]+dp[i-1][j-1][2];
+                    }
+                }
+            }
+        }
+        System.out.println(dp[n-1][n-1][0]+dp[n-1][n-1][1]+dp[n-1][n-1][2]);
+    }
+
+}
diff --git a/src/CLASS/D24/KnapsackTest.java b/src/CLASS/D24/KnapsackTest.java
new file mode 100644
index 0000000..e5ccaad
--- /dev/null
+++ b/src/CLASS/D24/KnapsackTest.java
@@ -0,0 +1,33 @@
+package CLASS.D24;
+
+import java.util.Scanner;
+
+public class KnapsackTest {
+    public static void main(String[] args) {
+        Scanner sc= new Scanner(System.in);
+        int n= sc.nextInt();
+        int w=sc.nextInt();
+
+        int [] weights= new int[n+1];
+        int [] profits=new int[n+1];
+
+        for (int i = 0; i <=n; i++) {
+            weights[i]= sc.nextInt();
+            profits[i]=sc.nextInt();
+        }
+        int[][]d= new int[n+1][w+1];
+
+        for (int i = 1; i <=n ; i++) {
+            for (int j = 1; j <=n; j++) {
+                if(weights[i]>j){
+                    d[i][j]=d[i-1][j];
+                }
+                else{
+                    d[i][j]=Math.max(d[i-1][j], profits[i]+d[i-1][j-weights[i]]);
+                }
+            }
+        }
+        System.out.println(d[n][w]);
+
+    }
+}
diff --git "a/src/CLASS/D24/boj/prob12865_\355\217\211\353\262\224\355\225\234\353\260\260\353\202\255.java" "b/src/CLASS/D24/boj/prob12865_\355\217\211\353\262\224\355\225\234\353\260\260\353\202\255.java"
new file mode 100644
index 0000000..aaee032
--- /dev/null
+++ "b/src/CLASS/D24/boj/prob12865_\355\217\211\353\262\224\355\225\234\353\260\260\353\202\255.java"
@@ -0,0 +1,37 @@
+package CLASS.D24.boj;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class prob12865_평범한배낭 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st=new StringTokenizer(in.readLine()," ");;
+        int n=Integer.parseInt(st.nextToken());
+        int k=Integer.parseInt(st.nextToken());
+
+        int w[]=new int[n+1];
+        int v[]=new int[n+1];
+        for (int i = 1; i <= n; i++) {
+            st=new StringTokenizer(in.readLine()," ");
+            w[i]=Integer.parseInt(st.nextToken());
+            v[i]=Integer.parseInt(st.nextToken());
+        }
+
+        int[][] dp=new int[n+1][k+1];
+        for (int i = 1; i < n+1; i++) {
+            for (int j = 1; j < k+1; j++) {
+                if(j>=w[i]){
+                    dp[i][j]=Math.max(dp[i-1][j],v[i]+dp[i-1][j-w[i]]);
+                }
+                else{
+                    dp[i][j]=dp[i-1][j];
+                }
+            }
+        }
+        System.out.println(dp[n][k]);
+    }
+}
+
diff --git a/src/CLASS/D25/boj/LISTest.java b/src/CLASS/D25/boj/LISTest.java
new file mode 100644
index 0000000..ae6222b
--- /dev/null
+++ b/src/CLASS/D25/boj/LISTest.java
@@ -0,0 +1,28 @@
+package CLASS.D25.boj;
+
+import java.util.Scanner;
+
+public class LISTest {
+    public static void main(String[] args) {
+        Scanner sc= new Scanner(System.in);
+        int n= sc.nextInt();
+        int []arr=new int[n];
+        int []lis=new int[n];
+
+        for (int i = 0; i < n; i++) {
+            arr[i]=sc.nextInt();
+        }
+
+        int max=0;
+        for (int i = 0; i < n; i++) {
+            lis[i]=1;
+            for (int j = 0; j < i; j++) {
+                if(arr[j]<arr[i]&&lis[i]<lis[j]+1){
+                    lis[i]=lis[j]+1;
+                }
+            }
+            if(max<lis[i]) max=lis[i];
+        }
+        System.out.println(max);
+    }
+}