#!/bin/python

import sys

def collinear(p0, p1, p2):
    x1, y1 = p1[0] - p0[0], p1[1] - p0[1]
    x2, y2 = p2[0] - p0[0], p2[1] - p0[1]
    return x1 * y2 - x2 * y1 < 1e-12
n = int(raw_input().strip())
points=[]
for a0 in xrange(n):
    x,y = raw_input().strip().split(' ')
    points.append([int(x),int(y)])
f=1
for i in range(n):
    for j in range(i+1,n):
        for k in range(j+1,n):
            
            if not collinear(points[i],points[j],points[k]):
                f=0
                break
if f:print "YES"
else:print "NO"