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

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.StringTokenizer;

public class Main {

    public static void main(String[] args) throws IOException {
        new Main().run();
    }

    StringTokenizer str = null;
    BufferedReader in;
    PrintWriter out;

    void run() throws IOException {
        in = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(new OutputStreamWriter(System.out));
        solve();
        out.flush();
        out.close();
    }

    String nextString() throws IOException {
        return in.readLine();
    }

    String nextToken() throws IOException {
        if (str == null || !str.hasMoreElements()) {
            str = new StringTokenizer(nextString());
        }
        return str.nextToken();
    }

    int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }

    class Point implements Comparable<Point> {
        int x;
        int y;

        @Override
        public int compareTo(Point p) {
            if (p.x > x)
                return -1;
            if (p.x < x)
                return 1;
            if (p.y > y)
                return -1;
            if (p.y < y)
                return 1;
            return 0;
        }
    }

    void solve() throws IOException {
        int n = nextInt();
        Point p[] = new Point[n];
        for (int i = 0; i < n; i++) {
            Point pp = new Point();
            pp.x = nextInt();
            pp.y = nextInt();
            p[i] = pp;
        }
        Arrays.sort(p);
        int k = 0;
        double r[][] = new double[n][n];
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < n; j++) {
                r[j][i] = r[i][j] = R(p, i, j);
            }
        }
        for (int i = 0; i < n; i++) {
            for (int j = i + 2; j < n; j++) {
                double d = r[i][j] / 2.0D;

                int a = p[j].y - p[i].y;
                int b = p[i].x - p[j].x;
                int c = p[i].x * p[j].y - p[j].x * p[i].y;

                for (int l = i + 1; l < j; l++) {
                    if (p[l].x * a + p[l].y * b + c == 0) {
                        if (Math.abs(r[i][l] - r[j][l]) < 0.00001) {
                            k++;
                            continue;
                        }
                        if (d < r[i][l])
                            continue;
                    }
                }
            }
        }
        out.println(k);
    }

    private double R(Point p[], int i, int l) {
        int xx = p[i].x - p[l].x;
        int yy = p[i].y - p[l].y;
        xx = xx * xx;
        yy = yy * yy;
        return Math.sqrt(xx + yy);
    }

    private boolean P(Point p[], int i, int j, int l) {
        return (p[i].y - p[j].y) * p[l].x + (p[j].x - p[i].x) * p[l].y
                + (p[i].x * p[j].y - p[j].x * p[i].y) == 0;
    }

}