#!/bin/python

import sys

def on_line(n, points):
    if n <= 1: 
        print("YES")
    elif points[0][0] == points[1][0]: # same x's
        for point in points:
            if points[0][0] != point[0]:
                print("NO")
                return
        print("YES")
        return
    elif points[0][1] == points[1][1]: #same y's
        for point in points:
            if points[0][1] != point[1]:
                print("NO")
                return
        print("YES")
        return
    print("NO")
    return

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