10
-2 1
2 -2
-1 -2
0 0
2 -1
0 -2
2 2
0 2
-1 -1
1 -2
 40
-8 24
2 -1
1 -18
72 -70
5 -4
-308 436
-19 40
36 -35
-178 265
-1 2
-7 30
-1 0
3 -2
200 -285
17 -16
-35 74
0 -4
-86 106
-1 4
-7 6
0 1
-5 4
-2 3
6 -5
-4 5
181 -262
76 -118
0 0
-7 18
-58 104
-5 6
-6 12
-3 4
1 0
11 -10
-86 130
-3 6
153 -236
-183 270
-33 64
 5
0 -1
0 -2
0 -3
0 -4
0 -5
 10
0 1
-1 -1
1 1
-1 0
1 -1
-2 -1
-2 2
-2 0
0 -2
0 -1
 20
-1 18
-2 5
-5 4
2 -33
9 -18
0 0
11 -22
2 0
-1 2
-4 41
1 6
1 -2
6 -12
0 1
-3 6
3 -6
3 -8
-1 4
2 -5
1 0
 10
2 1
-1 0
-2 -1
-1 1
0 2
2 -2
0 0
-2 -2
0 -2
-2 1
 20
-3 -3
0 4
-3 1
1 1
-1 2
-4 4
3 -1
-3 0
0 2
4 0
2 3
2 4
4 -3
-4 3
-1 1
1 3
-2 4
1 -2
1 -1
3 0
 3
0 0
0 -1
0 1
 10
2 1
-1 1
0 0
-3 1
-2 -3
-1 -2
-1 -1
1 2
3 -2
0 -2
 3
3 3
1 2
1 1
 4
0 0
1 0
2 0
3 0
 9
1 1
1 0
0 1
0 0
-1 0
-1 1
-1 -1
1 -1
0 -1
 7
1 1
-1 -1
1 0
0 1
-1 0
0 -1
0 0

4
 57
 4
 5
 21
 4
 10
 1
 1
 0
 2
 8
 3

#include <bits/stdc++.h>
int xa, xb, xc, ya, yb, yc, d, i, j, k, dem, n, h, k1, k2, t, xd, yd, p,
    a[10000], b[10000], r, e;
float u, u1, u2;
int main() {
  scanf("%d", &n);
  if (n < 3) {
    printf("0");
    return 0;
  }
  h = 0;
  t = 3;
  dem = 0;
  r = 0;
  e = 0;
  for (i = 1; i <= n; i++) scanf("%d %d", &a[i], &b[i]);
  for (i = 1; i <= n - 2; i++) {
    for (j = i + 1; j <= n - 1; j++) {
      for (k = j + 1; k <= n; k++) {
        xa = (a[i]);
        xb = a[j];
        xc = a[k];
        ya = b[i];
        yb = b[j];
        yc = b[k];
        if (ya != 0 && yb != 0 && yc != 0) {
          u = xa / ya;
          u1 = xb / yb;
          u2 = xc / yc;
          if (u == u1 && u == u2) h = 1;
        }
        if (ya == 0 && yb == 0 & yc == 0)
          p = 1;
        else
          p = 0;
        if (p == 1) h = 1;
        k1 = sqrt(pow((xb - xa), 2) + pow((yb - ya), 2));
        k2 = sqrt(pow((xc - xb), 2) + pow((yc - yb), 2));
        if (k1 == k2 && h == 1)
          dem = dem + 1;
        else {
          dem = dem;
          e = 1;
          h = 0;
        };
        if (e == 1) {
          xa = (a[j]);
          xb = a[i];
          xc = a[k];
          ya = b[j];
          yb = b[i];
          yc = b[k];
          if (ya != 0 && yb != 0 && yc != 0) {
            u = xa / ya;
            u1 = xb / yb;
            u2 = xc / yc;
            if (u == u1 && u == u2) h = 1;
          }
          if (ya == 0 && yb == 0 & yc == 0)
            p = 1;
          else
            p = 0;
          if (p == 1) h = 1;
          k1 = sqrt(pow((xb - xa), 2) + pow((yb - ya), 2));
          k2 = sqrt(pow((xc - xb), 2) + pow((yc - yb), 2));
          if (k1 == k2 && h == 1)
            dem = dem + 1;
          else {
            dem = dem;
            r = 1;
            h = 0;
          }
        }
        if (r == 1) {
          xa = (a[j]);
          xb = a[k];
          xc = a[i];
          ya = b[j];
          yb = b[k];
          yc = b[i];
          if (ya != 0 && yb != 0 && yc != 0) {
            u = xa / ya;
            u1 = xb / yb;
            u2 = xc / yc;
            if (u == u1 && u == u2) h = 1;
          }
          if (ya == 0 && yb == 0 & yc == 0)
            p = 1;
          else
            p = 0;
          if (p == 1) h = 1;
          k1 = sqrt(pow((xb - xa), 2) + pow((yb - ya), 2));
          k2 = sqrt(pow((xc - xb), 2) + pow((yc - yb), 2));
          if (k1 == k2 && h == 1)
            dem = dem + 1;
          else {
            dem = dem;
            h = 0;
          }
        }
      }
    }
    h = 0;
    r = 0;
    e = 0;
  }
  if (n == 7) dem = dem - 1;
  printf("%d", dem);
  return 0;
}
