package backjoon;

// https://www.acmicpc.net/problem/11651

// 좌표 정렬하기 2

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.Arrays;

import java.util.Comparator;

import java.util.StringTokenizer;

public class _11651 {

public static void main(String[] args) throws IOException {

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

int N = Integer.parseInt(br.readLine());

//memory 73392 runtime 764

int[][] arr = new int[N][2];

StringTokenizer st;

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

// 위치 주의

st = new StringTokenizer(br.readLine());

arr[i][1] = Integer.parseInt(st.nextToken());

arr[i][0] = Integer.parseInt(st.nextToken());

}

Arrays.sort(arr, (e1, e2) -> {

if(e1[0] == e2[0]) {

return e1[1] - e2[1];

} else {

return e1[0] - e2[0];

}

});

StringBuilder sb = new StringBuilder();

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

// 위치 주의

sb.append(arr[i][1] + " " + arr[i][0]).append('\n');

}

System.out.println(sb);

}

}