package algorithm;

import java.util.*;

public class GraphMatrix {

static int N;

static int[][] g;

static boolean[] v;

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

N = sc.nextInt();

int E = sc.nextInt();

g = new int[N][N]; //

v = new boolean[N];

for (int i = 0; i < E; i++) {

int from = sc.nextInt();

int toto = sc.nextInt();

g[from][toto] = g[toto][from] = 1; //

}

for (int[] a : g)

System.out.println(Arrays.toString(a));

System.out.println();

bfs(0);

// dfs(0);

sc.close();

}

static void bfs(int i) {

ArrayDeque<Integer> q = new ArrayDeque<>();

v[i] = true;

q.offer(i);

while (!q.isEmpty()) { //

i = q.poll();

System.out.print((char) (i + 'A') + " ");

for (int j = 0; j < N; j++) { //

if (g[i][j] != 0 && !v[j]) {

v[j] = true;

q.offer(j);

}

}

}

}

static void dfs(int i) {

v[i] = true;

System.out.print((char) (i + 'A') + " ");

for (int j = 0; j < N; j++) { //

if (g[i][j] != 0 && !v[j])

dfs(j);

}

}

}

/*

* 7

* 8

* 0 1

* 0 2

* 1 3

* 1 4

* 3 5

* 4 5

* 5 6

* 2 6

*

* A0

* / \

* B1 C2

* / \ /\

* D3 E4 \

* \ / \

* F5 -- G6

*/