#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int N = 25;
int x[N], y[N], d[10];
int dis(int a, int b) {
    return (x[a] - x[b]) * (x[a] - x[b]) + (y[a] - y[b]) * (y[a] - y[b]);
}
int main() {
    int n;
    while (scanf("%d", &n) != EOF) {
        for (int i = 1; i <= n; ++i)    scanf("%d%d", &x[i], &y[i]);
        int ans = 0;
        for (int i = 1; i <= n; ++i)
            for (int j = 1; j < i; ++j)
                for (int k = 1; k < j; ++k)
                    for (int l = 1; l < k; ++l) {
                        d[1] = dis(i, j), d[2] = dis(i, k), d[3] = dis(i, l);
                        d[4] = dis(j, k), d[5] = dis(j, l), d[6] = dis(k, l);
                        sort(d + 1, d + 7);
                        bool f = 1;
                        for (int i = 2; i <= 4; ++i)
                            if (d[i] != d[1])    f = 0;
                        if (d[5] != d[6] || 2 * d[1] != d[5])    f = 0;
                        if (f) ++ans;
                    }
        printf("%d\n", ans);
    }
    return 0;
}