#!/bin/python3

import sys


n = int(input().strip())
x1, y1 = None, None
xyList = []
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    xyList.append([x, y])

allXSame = True
allYSame = True
for x, y in xyList:
    if x1 is None and y1 is None:
        x1, y1 = x, y
    else:
        if x != x1:
            allXSame = False
        if y != y1:
            allYSame = False
print('YES' if (allXSame or allYSame) else 'NO')