#!/bin/python3

xSet = set()
ySet = set()
coordList = []
n = int(input().strip())
for a in range(n):
    x, y = input().strip().split(' ')
    x, y = [int(x), int(y)]
    coordList.append((x,y))

for i in coordList:
    xSet.add(i[0])
    ySet.add(i[1])

if len(xSet) == 1 or len(ySet) == 1:
    print("YES")
else:
    print("NO")