#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
using Slope = pair<ll, ll>;
const int M = 20;
map<Slope, int> cnt;
bool match[M];
ll m, x[M], y[M];
ll ans;
void DFS(int level) {
    if(level == m) {
        ll res = 0;
        for(auto P : cnt) {
            res += (P.second * (P.second - 1)) / 2;
        }
        ans = max(res, ans);
        return;
    }

    if(match[level]) {
        DFS(level + 1);
        return;
    }

    for(int i = level + 1; i < m; i++) {
        if(match[i]) continue;

        match[i] = true;
        match[level] = true;
        ll dif_x = x[level] - x[i];
        ll dif_y = y[level] - y[i];

        if(dif_x < 0) {
            dif_x *= -1;
            dif_y *= -1;
        }

        if(dif_x == 0) {
            dif_y = 1;
        } else {
            ll gd = __gcd(dif_x, dif_y);
            dif_x /= gd;
            dif_y /= gd;
        }

        cnt[{dif_x, dif_y}]++;
        DFS(level + 1);

        cnt[{dif_x, dif_y}]--;

        if(cnt[{dif_x, dif_y}] == 0) {
            cnt.erase({dif_x, dif_y});
        }
        match[i] = false;
        match[level] = false;
    }
}
int main() {
    cin >> m;
    for(int i = 0; i < m; i++) {
        cin >> x[i] >> y[i];
    }

    DFS(0);

    cout << ans << "\n";
}