#89 백준 파이썬 [11650] 좌표 정렬하기

https://www.acmicpc.net/problem/11650

 

 

#Solution

N = int(input())
dot_list = []

for _ in range(N):
    dot_list.append(list(map(int, input().split())))
    
dot_list.sort(key = lambda dot: (dot[0], dot[1]))
for [i, j] in dot_list:
    print(i, j)