Vanya got bored and he painted *n* distinct points on the plane. After that he connected all the points pairwise and saw that as a result many triangles were formed with vertices in the painted points. He asks you to count the number of the formed triangles with the non-zero area.
The first line contains integer *n* (1 ≤ *n* ≤ 2000) — the number of the points painted on the plane. 

Next *n* lines contain two integers each *x*<sub class="lower-index">*i*</sub>, *y*<sub class="lower-index">*i*</sub> ( - 100 ≤ *x*<sub class="lower-index">*i*</sub>, *y*<sub class="lower-index">*i*</sub> ≤ 100) — the coordinates of the *i*-th point. It is guaranteed that no two given points coincide.
import itertools

n=int(input())
c=[]
for x in range(n):
	c.append(input())
d=dict()
for z in list(itertools.combinations(c,2)):
	z0x,z0y=map(int,z[0].split())
	z1x,z1y=map(int,z[1].split())
	datos=[]
	m=(z1y-z0y)/(z1x-z0x) if (z1x-z0x)!=0 else "v"
	b=z0y-m*z0x if m!="v" else z0x
	try:
		d[(m,b)]+=1
	except KeyError:
		d[(m,b)]=1

ans=n*(n-1)*(n-2)/6
for x in d:
	t=d[x]
	ans-=t*(t-1)*(t-2)/6
print(int(ans))