#include <stdio.h>

int main() {
    int n;
    scanf("%d",&n);
    int cordinate[n][2];
    for (int i=0; i<n; i++) {
        scanf("%d %d",&cordinate[i][0],&cordinate[i][1]);
    }
    for (int i=0; i<n-1 ;i++) {
        for (int j=0; j<n-1-i; j++) {
            //x다를때
            if (cordinate[j][0]>cordinate[j+1][0] || (cordinate[j][0]==cordinate[j+1][0] && cordinate[j][1]>cordinate[j+1][1])) {
                int tmp_x=cordinate[j][0];
                cordinate[j][0]=cordinate[j+1][0];
                cordinate[j+1][0]=tmp_x;
                
                int tmp_y=cordinate[j][1];
                cordinate[j][1]=cordinate[j+1][1];
                cordinate[j+1][1]=tmp_y;
            }
        }
    }
    for (int i=0; i<n; i++) {
        printf("%d %d\n",cordinate[i][0],cordinate[i][1]);
    }
    return 0;
}