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.

# coding: utf-8

# In[15]:


def getArea(puntos):
    a = 0
    for i in range(len(puntos)):
        a+= (puntos[i][0]*puntos[(i+1)%len(puntos)][1])-(puntos[(i+1)%len(puntos)][0]*puntos[i][1])
    return a/2

n = int(input())
puntos=[]
for i in range(n):
    a = input()
    b = list(map(int,a.split()))
    puntos.append(b)
posibles = []
cuenta = 0
for i in range(len(puntos)):
    for j in range(i+1,len(puntos)):
        for k in range(j+1, len(puntos)):
            tmp = [puntos[i],puntos[j],puntos[k]]
            posibles.append(tmp)
            if getArea(tmp)!=0:
                cuenta+=1

print(cuenta)

            
    

