#!/bin/python3

import sys


n = int(input().strip())
X = []
Y = []
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    X += [x]
    Y += [y]

xans = True
for x in X:
    if x != X[0]:
        xans = False

yans = True
for y in Y:
    if y != Y[0]:
        yans = False

if xans + yans > 0:
    print("YES")
else:
    print("NO")