main.py

from functools import cmp_to_key

def my_cmp(a, b):
    if a[1] != b[1]:
        return a[1] - b[1]
    return a[0] - b[0]

n = int(input())
arr = [list(map(int, input().split())) for _ in range(n)]
arr.sort(key=cmp_to_key(my_cmp))

for k in arr:
    print(k[0], k[1])