#!/bin/python3

import sys



n = int(input().strip())
a =[0]*(n-1)
b=  []
for a0 in range(n):
    x,y = input().strip().split(' ')
    x,y = int(x),int(y)
    b.append((x,y))
c = 0
for i in range(n-1):
    if b[i][0] != b[i+1][0]:
        a[i] = (b[i+1][1] - b[i][1])/(b[i+1][0] - b[i][0])
    else:
        a[i] = 'o'
f = 1
for i in range(len(a)):
    if a[i] != 'o' and a[i] != 0:
        f=  0
        break
if f == 0:
    print("NO")
else:
    print("YES")