#!/bin/python3

import sys

def is_vertical(points):
    for x, _ in points[1:]:
        if points[0][0] != x:
            return False
    return True

def is_horizontal(points):
    for _, y in points[1:]:
        if points[0][1] != y:
            return False
    return True

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

if not (is_horizontal(points) or is_vertical(points)):
    print("NO")
else:
    print("YES")