#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; //#define int long long typedef long long ll; typedef unsigned long long ul; typedef unsigned int ui; constexpr ll mod = 1000000007; const ll INF = mod * mod; typedef pairP; #define stop char nyaa;cin>>nyaa; #define rep(i,n) for(int i=0;i=0;i--) #define Rep(i,sta,n) for(int i=sta;i=1;i--) #define Rep1(i,sta,n) for(int i=sta;i<=n;i++) #define all(v) (v).begin(),(v).end() typedef pair LP; typedef long double ld; typedef pair LDP; const ld eps = 1e-12; const ld pi = acos(-1.0); ll mod_pow(ll x, ll n, ll m) { ll res = 1; while (n) { if (n & 1)res = res * x % m; x = x * x % m; n >>= 1; } return res; } struct modint { ll n; modint() :n(0) { ; } modint(ll m) :n(m) { if (n >= mod)n %= mod; else if (n < 0)n = (n % mod + mod) % mod; } operator int() { return n; } }; bool operator==(modint a, modint b) { return a.n == b.n; } modint operator+=(modint& a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; } modint operator-=(modint& a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; } modint operator*=(modint& a, modint b) { a.n = ((ll)a.n * b.n) % mod; return a; } modint operator+(modint a, modint b) { return a += b; } modint operator-(modint a, modint b) { return a -= b; } modint operator*(modint a, modint b) { return a *= b; } modint operator^(modint a, int n) { if (n == 0)return modint(1); modint res = (a * a) ^ (n / 2); if (n % 2)res = res * a; return res; } ll inv(ll a, ll p) { return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p); } modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); } const int max_n = 1 << 17; modint fact[max_n], factinv[max_n]; void init_f() { fact[0] = modint(1); for (int i = 0; i < max_n - 1; i++) { fact[i + 1] = fact[i] * modint(i + 1); } factinv[max_n - 1] = modint(1) / fact[max_n - 1]; for (int i = max_n - 2; i >= 0; i--) { factinv[i] = factinv[i + 1] * modint(i + 1); } } modint comb(int a, int b) { if (a < 0 || b < 0 || a < b)return 0; return fact[a] * factinv[b] * factinv[a - b]; } void solve() { int n; cin >> n; vector x(n), y(n); rep(i, n)cin >> x[i] >> y[i]; auto calc = [&](int i, int j, int k) { return (x[j] - x[i]) * (y[k] - y[i]) - (x[k] - x[i]) * (y[j] - y[i]); }; modint ans = 0; rep(s, n) { vector> vs; rep(i, n)if (i != s) { ld t = atan2(y[i] - y[s], x[i] - x[s]); vs.push_back({ t,i }); } sort(all(vs)); int sz = n - 1; rep(i, sz)vs.push_back({ vs[i].first + 2 * pi,vs[i].second }); vector rx(2 * sz + 1), ry(2 * sz + 1); rep(i, 2 * sz) { int id = vs[i].second; rx[i + 1] = rx[i] + (modint)x[id]; ry[i + 1] = ry[i] + (modint)y[id]; } int loc = 0; rep(i, sz) { int id = vs[i].second; while (vs[loc].first <= vs[i].first + pi) { loc++; } int cp = loc - i - 1; int cn = n - 2 - cp; ans += (ll)(cp - cn) * (x[s] * y[id] - y[s] * x[id]); ll sx = rx[loc] - rx[i + 1]; ans += -sx * (y[id] - y[s]); ll sy = ry[loc] - ry[i + 1]; ans += sy * (x[id] - x[s]); sx = rx[sz]-(modint)x[id] - (modint)sx; ans += sx * (y[id] - y[s]); sy = ry[sz]-(modint)y[id] - (modint)sy; ans -= sy * (x[id] - x[s]); } //cout << s << " " << ans << "\n"; } ans *= (1 + mod) / 6; cout << ans << "\n"; } signed main() { ios::sync_with_stdio(false); cin.tie(0); //cout << fixed << setprecision(10); //init_f(); //init(); //int t; cin >> t; rep(i, t) //init(); solve(); return 0; }