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.
n = int(input())
lis = []
c = 0
for i in range(n):
    lis.append(tuple(map(int,input().split())))
for i in range(n-2):
    for e in range(i+1,n-1):
        for k in range(e+1,n):
            try:
                if (lis[i][1]-lis[e][1])/(lis[i][0]-lis[e][0]) != (lis[e][1]-lis[k][1])/(lis[e][0]-lis[k][0]):
                    c+=1
                    
            except:
                if (lis[i][0]-lis[e][0]) == lis[i][0]-lis[k][0]:
                    c+=1
                    
        
print(c)
