#!/bin/python

import sys

n = int(raw_input().strip())
a = [None]*n
for i in xrange(n):
    x,y = raw_input().strip().split(' ')
    a[i] = (int(x), int(y))
colinear = True
if (a[1][0] - a[0][0]) == 0:
    x_intercept = a[0][0]
    for x, y in a:
        if x != x_intercept:
            colinear = False
elif (a[1][1] - a[0][1]) == 0: 
    y_intercept = a[0][1]
    for x, y in a:
        if y != y_intercept:
            colinear = False
else:
    colinear = False
ret = 'YES' if colinear else 'NO'
print ret