n=int(raw_input())
x,y=map(int,raw_input().split())
a,b=map(int,raw_input().split())
flag=True
if a==x:
    sl=float('inf')
else:
    sl=float(b-y)/(a-x)
for i in xrange(2,n):
    a,b=map(int,raw_input().split())
    if a==x:
        if sl!=float('inf'):
            flag=False
            break
    else:
        if float(b-y)/(a-x)!=sl:
            print 'NO'
            flag=False
            break
if flag:
    print 'YES'