#include <fstream>
#include <set>

using namespace std;

#define mod 1001

typedef struct {
    int x;
    int y;
} cutzu;

int N;
cutzu v[1005];
set <pair <int, int> > H;

void Citire () {
    ifstream fin ("patrate3.in");
    fin >> N;
    char pars[100];
    char dummy[10];
    fin.getline (dummy, 7);
    int j, e, e1;
    for (int i = 0; i < N; i++)
    {
        fin.getline (pars, 90);
        j = 0;
        e = 1;
        e1 = 1;
        if (pars[j] == '-') e = -1, j++;
        for (; pars[j] != '.'; j++)
            v[i].x = v[i].x * 10 + pars[j] - '0';
        j++;
        for (int k = j; k <= j + 3; k++)
            v[i].x = v[i].x * 10 + pars[k] - '0';

        j = j + 5;
        if (pars[j] == '-') e1 = -1, j++;
        for (; pars[j] != '.'; j++)
            v[i].y = v[i].y * 10 + pars[j] - '0';
        j++;
        for (int k = j; k <= j + 3; k++)
            v[i].y = v[i].y * 10 + pars[k] - '0';
        v[i].x *= e;
        v[i].y *= e1;
        H.insert (make_pair (v[i].x, v[i].y));
    }
    fin.close ();
}

int Business () {
    int x1, y1;
    int xlol, ylol, x1p, y1p, xp, yp;
    int cnt = 0;
    cutzu u, t;
    for (int i = 0; i < N; i++)
    {
        for (int j = i + 1; j < N; j++)
        {
            if (v[i].y >= v[j].y) xlol = v[i].x, ylol = v[i].y, x1 = v[j].x, y1 = v[j].y;
			else xlol = v[j].x, ylol = v[j].y, x1 = v[i].x, y1 = v[i].y;

			yp = ylol - (xlol - x1);
			y1p = y1 - (xlol - x1);

			xp = xlol + (ylol - y1);
			x1p = x1 + (ylol - y1);
            u.x = xp;
            u.y = yp;
            t.x = x1p;
            t.y = y1p;
            if (H.find (make_pair (u.x, u.y)) != H.end () && H.find (make_pair (t.x, t.y)) != H.end ()) cnt++;
        }
    }
    return cnt >> 1;
}

void Scriere () {
    ofstream fout ("patrate3.out");
    fout << Business ();
    fout.close ();
}

int main () {
    Citire ();
    Scriere ();
    return 0;
}