#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define all(a) a.begin(),a.end() #define rep(i, n) for (ll i = 0; i < (n); i++) #define pb push_back #define debug(x) cerr << #x << ':' << x << '\n' #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") using namespace std; typedef long long ll; typedef unsigned long long ull; typedef long double ld; typedef pair P; typedef complex com; constexpr int inf = 1000000010; constexpr ll INF = 1000000000000000010; constexpr ld eps = 1e-12; constexpr ld pi = 3.141592653589793238; template inline bool chmax(T &a, const U &b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(T &a, const U &b) { if (a > b) { a = b; return true; } return false; } constexpr ll mod = 1000000007; int main() { cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); int n; cin >> n; vector x(n), y(n); rep(i, n) cin >> x[i] >> y[i]; ll ans = 0; rep(i, n) { rep(j, i) { rep(k, j) { int tmp = (x[j] - x[i])*(y[k] - y[i]) - (y[j] - y[i])*(x[k] - x[i]); if (tmp < 0) tmp = -tmp; ans += tmp; if (ans >= mod) ans -= mod; } } } cout << ans << '\n'; }