#!/bin/python3

import sys


n = int(input().strip())
isOnHorizontal = True
isOnVertical = True
xs = []
ys = []
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    xs.append(x)
    ys.append(y)

xVert = xs[0]
for i in range(1, len(xs)):
    if xs[i] != xVert:
        isOnVertical = False
        break

yHori = ys[0]
for i in range(1, len(ys)):
    if ys[i] != yHori:
        isOnHorizontal = False
        break
        
if isOnVertical or isOnHorizontal:
    print("YES")
else:
    print("NO")