#!/bin/python3

import sys

is_vertical = True
is_horizontal = True
x_0 = 0
y_0 = 0

n = int(input().strip())
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = [int(x),int(y)]
    if (a0 == 0):
        x_0 = x
        y_0 = y
    if x != x_0:
        is_horizontal = False
    if y != y_0:
        is_vertical = False

if is_vertical or is_horizontal:
    print("YES")
else:
    print("NO")