import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Back_11651 {
    public static void main(String[] args) throws IOException {

        // given
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        int N = Integer.parseInt(br.readLine());
        int arr[][] = new int[N][2];

        for (int i = 0; i < N; i++) {
            st = new StringTokenizer(br.readLine());
            arr[i][1] = Integer.parseInt(st.nextToken());
            arr[i][0] = Integer.parseInt(st.nextToken());
        }
        // when
        Arrays.sort(arr, (e1, e2) -> {
            if (e1[0] == e2[0]) {
                return e1[1] - e2[1];
            } else {
                return e1[0] - e2[0];
            }
        });

        // then
        for (int i = 0; i < N; i++) {
            System.out.println(arr[i][1] + " " + arr[i][0]);
        }
        br.close();
    }
}