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.
numeroPuntos=int(input())
conclusion=0
listaX=[0]
listaY=[0]
listaDifX=[[0 for i in range(2000)] for j in range(2000)]
listaDifY=[[0 for i in range(2000)] for j in range(2000)]
#for i in range(0,numeroPuntos):
for i in range(1, numeroPuntos + 1):
    listaT=list(map(int,(input().split())))
    listaX.append(listaT[0])
    listaY.append(listaT[1])
for i in range(1, numeroPuntos):
    for j in range(i+1,numeroPuntos+1):
        listaDifX[i][j]= listaX[i] - listaX[j]
        listaDifY[i][j]= listaY[i] - listaY[j]
#for i in range(0,numeroPuntos):
for i in range(1, numeroPuntos - 1):
    #while (j<numeroPuntos):
    for j in range(i, numeroPuntos):
        #while (k<numeroPuntos):
        for k in range(j+1, numeroPuntos + 1):
            #print(i,j,k)
            #colinear = (abs((punto2[0] - punto1[0]) * (punto3[1] - punto1[1]) - (punto3[0] - punto1[0]) * (punto2[1] - punto1[1])))
            if ( abs(listaDifX[i][j] * listaDifY[i][k] - listaDifX[i][k] * listaDifY[i][j]) != 0):
                conclusion+=1
print(conclusion)