import math
import os
import random
import re
import sys

def line(arr_x,arr_y):
    if len(set(arr_x)) == 1:
        return "YES"
    elif len(set(arr_y)) == 1:
        return "YES"
    else:
        return "NO"
    
if __name__ == '__main__':
    n = int(input())
    arr_x = []
    arr_y = []
    for n_itr in range(n):
        xy = input().split()
        x = int(xy[0])
        y = int(xy[1])
        arr_x.append(x)
        arr_y.append(y)
    print(line(arr_x,arr_y))