// n m

// 1 1

// 2 2

// 3 3

// 4 4

// 4 4

import java.util.*;

public class Main {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

int n = sc.nextInt(); // n

int m = sc.nextInt(); // m

HashMap<Integer, Integer> map = new HashMap<>();

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

int id = sc.nextInt();

int score = sc.nextInt();

if (map.containsKey(id)) {

map.put(id, map.get(id) + score);

} else {

map.put(id, score);

}

}

List<Map.Entry<Integer, Integer>> list = new ArrayList<>(map.entrySet());

// 按照value排序

Collections.sort(list, (o1, o2) -> {

return o2.getValue() - o1.getValue();

});

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

System.out.println(list.get(i).getKey());

}

}

}

class TreeNode {

int val;

TreeNode left;

TreeNode right;

TreeNode(int x){val = x;}

}

class ListNode {

int val;

ListNode next;

public ListNode(int val) {

this.val = val;

}

}

class ListNodeTools {

public static ListNode getListNode(int[] nums) {

ListNode dummy = new ListNode(-1);

ListNode pre = dummy;

for (int num : nums) {

pre.next = new ListNode(num);

pre = pre.next;

}

return dummy.next;

}

public static void printListNode(ListNode node) {

String s = "";

ListNode p = node;

while (p != null) {

s += p.val + "->";

p = p.next;

}

System.out.println(s+"null");

}

}