#include<bits/stdc++.h>
using namespace std;
typedef pair<int, int> pii;
typedef long long ll;

inline int rd() {
    int x = 0;
    bool f = 0;
    char c = getchar();
    for (; !isdigit(c); c = getchar()) f |= (c == '-');
    for (; isdigit(c); c = getchar()) x = x * 10 + (c ^ 48);
    return f ? -x : x;
}

#define N 17
#define M 1007 
#define fr first
#define sc second

map<pii, int> f;

int gcd(int a, int b) {return b ? gcd(b, a % b) : a;}

pii operator - (const pii &a, const pii &b) {return {a.fr - b.fr, a.sc - b.sc};}
pii operator / (const pii &a, const int &k) {return {a.fr / k, a.sc / k};}

pii a[N];

bool vis[N];

int s[N][N], cnt[M];

int n, idcnt, ans, res;

inline int c2(int x) {return x * (x - 1) / 2;}

inline void add(int x) {res -= c2(cnt[x]); ++cnt[x]; res += c2(cnt[x]);}

inline void del(int x) {res -= c2(cnt[x]); --cnt[x]; res += c2(cnt[x]);}

// (m - 1)!! = 2027025 
void dfs(int p) {
    if (p == n / 2) {ans = max(ans, res); return;}
    int A = 0;
    for (int i = 1; i <= n; ++i) 
        if (!vis[i]) {vis[i] = true; A = i; break;}
    for (int i = A + 1; i <= n; ++i)
        if (!vis[i]) {
            vis[i] = true; add(s[A][i]); dfs(p + 1);
            vis[i] = false; del(s[A][i]);
        }
    vis[A] = false;
}

int main() {
    n = rd();
    for (int i = 1; i <= n; ++i) {a[i].fr = rd(); a[i].sc = rd();}
    for (int i = 1; i <= n; ++i)
        for (int j = i + 1; j <= n; ++j) {
            pii tmp = (a[i] < a[j] ? a[j] - a[i] : a[i] - a[j]);
            tmp = tmp / gcd(abs(tmp.fr), abs(tmp.sc));
            if (!f[tmp]) f[tmp] = ++idcnt;
            s[i][j] = f[tmp];
        }
    dfs(0);
    printf("%d\n", ans);
    return 0;
}