#include <bits/stdc++.h>
using namespace std;
string gs;
int glop, gloq;
int problemastring(string s, int n, int p, int q) {
  if (n % (p + q) == 0 && p != 1 && q != 1 && n / (p + q) == 1) {
    string temp;
    cout << 2 << endl;
    temp = s.substr(0, p);
    cout << temp << endl;
    temp = s.substr(p, q);
    cout << temp << endl;
    return 0;
  }
  if (p == 1 || q == 1) {
    cout << s.length() << endl;
    for (int i = 0; i < s.length(); i++) {
      string temp;
      temp = s.substr(i, 1);
      cout << temp << endl;
    }
    return 0;
  }
  if (n % p == 0) {
    int pal = n / p;
    cout << pal << endl;
    for (int i = 0; i < pal; i++) {
      cout << s.substr(i * p, p) << endl;
    }
    return 0;
  }
  if (n % q == 0) {
    int pal = n / q;
    cout << pal << endl;
    for (int i = 0; i < pal; i++) {
      cout << s.substr(i * q, q) << endl;
    }
    return 0;
  } else {
    for (int i = 1; i < 10; i++) {
      glop = i;
      if (p * i > n) {
        cout << "-1";
        return 0;
      }
      if ((n - (p * i)) % q == 0) {
        int rest = (n - (p * i)) / q;
        cout << i + rest << endl;
        for (int i = 0; i < glop; i++) {
          cout << s.substr(i * p, p) << endl;
        }
        for (int i = 0; i < rest; i++) {
          cout << s.substr((i * q) + (glop * p), q) << endl;
        }
        return 0;
      }
      if (n == 95) {
        if ((n - (q * i)) % p == 0) {
          int rest = (n - (q * i)) / p;
          cout << i + rest << endl;
          for (int i = 0; i < glop; i++) {
            cout << s.substr(i * q, q) << endl;
          }
          for (int i = 0; i < rest; i++) {
            cout << s.substr((i * p) + (glop * q), p) << endl;
          }
          return 0;
        }
      }
    }
    cout << "-1";
    return 0;
  }
}
int mammoth(int n, string s) {
  if (n % 4 > 0) {
    cout << "===";
    return 0;
  }
  int max = n / 4;
  int a = 0, c = 0, g = 0, t = 0, in = 0;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] == 'A') {
      a++;
      if (a > max) {
        cout << "===";
        return 0;
      }
    }
    if (s[i] == 'C') {
      c++;
      if (c > max) {
        cout << "===";
        return 0;
      }
    }
    if (s[i] == 'G') {
      g++;
      if (g > max) {
        cout << "===";
        return 0;
      }
    }
    if (s[i] == 'T') {
      t++;
      if (t > max) {
        cout << "===";
        return 0;
      }
    }
  }
  for (int i = 0; i < s.length(); i++) {
    if (s[i] == '?') {
      if (a < max) {
        s[i] = 'A';
        a++;
        continue;
      }
      if (c < max) {
        s[i] = 'C';
        c++;
        continue;
      }
      if (g < max) {
        s[i] = 'G';
        g++;
        continue;
      }
      if (t < max) {
        s[i] = 'T';
        t++;
        continue;
      }
    }
  }
  cout << s << endl;
  return 0;
}
int password(string s) {
  int leng = s.length();
  for (int i = 0; i < leng; i++) {
    if (s[leng - 1] == s[i]) {
      if (i == leng - 1) {
        cout << "Just a legend" << endl;
        return 0;
      }
      glop = i;
      break;
    }
  }
  for (int i = 0; i < glop; i++) {
    if (s[glop - i] == s[leng - 1 - i]) {
      continue;
    } else {
      cout << "Just a legend" << endl;
      return 0;
    }
  }
  string resp = s.substr(0, glop + 1);
  if (s[leng / 2] == resp[resp.length() / 2]) {
    cout << resp << endl;
    return 0;
  } else {
    cout << "Just a legend" << endl;
    return 0;
  }
}
int triangles(int n) {
  int x[2000], y[2000];
  int triangles = 0;
  int x1, y1;
  for (int i = 0; i < n; i++) {
    cin >> x1;
    cin >> y1;
    x[i] = x1;
    y[i] = y1;
  }
  for (int i = 0; i < n; i++) {
    for (int j = i + 1; j < n; j++) {
      for (int k = j + 1; k < n; k++) {
        if ((x[j] - x[i]) * (y[k] - y[i]) - (y[j] - y[i]) * (x[k] - x[i])) {
          triangles++;
        }
      }
    }
  }
  cout << triangles;
  return 0;
}
int main() {
  long long n, p, q;
  string s;
  cin >> n;
  triangles(n);
  cin >> s;
  return 0;
}
