#include using namespace std; using int64 = long long; const int mod = 998244353; const int64 infll = (1LL << 62) - 1; const int inf = (1 << 30) - 1; struct IoSetup { IoSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(10); cerr << fixed << setprecision(10); } } iosetup; template< typename T1, typename T2 > ostream &operator<<(ostream &os, const pair< T1, T2 >& p) { os << p.first << " " << p.second; return os; } template< typename T1, typename T2 > istream &operator>>(istream &is, pair< T1, T2 > &p) { is >> p.first >> p.second; return is; } template< typename T > ostream &operator<<(ostream &os, const vector< T > &v) { for(int i = 0; i < (int) v.size(); i++) { os << v[i] << (i + 1 != v.size() ? " " : ""); } return os; } template< typename T > istream &operator>>(istream &is, vector< T > &v) { for(T &in : v) is >> in; return is; } template< typename T1, typename T2 > inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); } template< typename T1, typename T2 > inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); } template< typename T = int64 > vector< T > make_v(size_t a) { return vector< T >(a); } template< typename T, typename... Ts > auto make_v(size_t a, Ts... ts) { return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...)); } template< typename T, typename V > typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) { t = v; } template< typename T, typename V > typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) { for(auto &e : t) fill_v(e, v); } template< typename F > struct FixPoint : F { explicit FixPoint(F &&f) : F(forward< F >(f)) {} template< typename... Args > decltype(auto) operator()(Args &&... args) const { return F::operator()(*this, forward< Args >(args)...); } }; template< typename F > inline decltype(auto) MFP(F &&f) { return FixPoint< F >{forward< F >(f)}; } /** * @brief Rational (有理数型) */ template< typename T > struct Rational { private: T num, den; static T gcd(T a, T b) { if(a < 0) a = -a; if(b < 0) b = -b; return std::__gcd(a, b); } void normalize() { if(num == 0) { den = 1; } else { T g = gcd(num, den); num /= g; den /= g; if(den < 0) { num = -num; den = -den; } } } public: Rational() : num(0), den(1) {} explicit Rational(const T &n) : num(n), den(1) {} explicit Rational(const T &n, const T &d) : num(n), den(d) { normalize(); } Rational &operator=(const T &n) { return assign(n, 1); } Rational &assign(const T &n, const T &d) { num = n; den = d; normalize(); return *this; } T numerator() const { return num; } T denominator() const { return den; } Rational &operator+=(const Rational &r) { T r_num = r.num, r_den = r.den; T g = gcd(den, r_den); den /= g; num = num * (r_den / g) + r_num * den; g = gcd(num, g); num /= g; den *= r_den / g; return *this; } Rational &operator-=(const Rational &r) { T r_num = r.num, r_den = r.den; T g = gcd(den, r_den); den /= g; num = num * (r_den / g) - r_num * den; g = gcd(num, g); num /= g; den *= r_den / g; return *this; } Rational &operator*=(const Rational &r) { T r_num = r.num, r_den = r.den; T g1 = gcd(num, r_den); T g2 = gcd(den, r_num); num = (num / g1) * (r_num / g2); den = (den / g2) * (r_den / g1); return *this; } Rational &operator/=(const Rational &r) { T r_num = r.num, r_den = r.den; T g1 = gcd(num, r_num); T g2 = gcd(den, r_den); num = (num / g1) * (r_den / g2); den = (den / g2) * (r_num / g1); if(den < 0) { num = -num; den = -den; } return *this; } Rational &operator+=(const T &i) { return (*this) += Rational{i}; } Rational &operator-=(const T &i) { return (*this) -= Rational{i}; } Rational &operator*=(const T &i) { return (*this) *= Rational{i}; } Rational &operator/=(const T &i) { return (*this) /= Rational{i}; } Rational operator+(const Rational &r) const { return Rational(*this) += r; } Rational operator-(const Rational &r) const { return Rational(*this) -= r; } Rational operator*(const Rational &r) const { return Rational(*this) *= r; } Rational operator/(const Rational &r) const { return Rational(*this) /= r; } Rational operator+(const T &i) const { return Rational(*this) += i; } Rational operator-(const T &i) const { return Rational(*this) -= i; } Rational operator*(const T &i) const { return Rational(*this) *= i; } Rational operator/(const T &i) const { return Rational(*this) /= i; } Rational operator-() const { return Rational{-num, den}; } Rational &operator++() { num += den; return *this; } Rational &operator--() { num -= den; return *this; } #define define_cmp(op) \ bool operator op (const Rational& r) const { return num * r.den op r.num * den; } \ bool operator op (const T& i) const { return num op i * den; } define_cmp(==) define_cmp(!=) define_cmp(<) define_cmp(>) define_cmp(<=) define_cmp(>=) #undef define_cmp template< typename Real = double > Real to_double() const { return static_cast < Real >(numerator()) / denominator(); } Rational abs() const { return Rational{num < 0 ? -num : num, den}; } friend ostream &operator<<(ostream &os, const Rational &r) { return os << r.numerator() << "/" << r.denominator(); } }; template< typename T > struct Point { T x, y; Point() : x(0), y(0) {} Point(const T& x, const T& y) : x(x), y(y) {} int dir() const { if(y < 0) return -1; if(y == 0 and x >= 0) return 0; return 1; } }; template< typename T > T cross(const Point< T >& a, const Point< T >& b) { return a.x * b.y - a.y * b.x; } template< typename T > vector< int > arg_sort(const vector< Point< T > >& ps) { vector< int > ord(ps.size()); iota(begin(ord), end(ord), 0); sort(begin(ord), end(ord), [&](int a, int b) { if(ps[a].dir() != ps[b].dir()) return ps[a].dir() < ps[b].dir(); return cross(ps[a], ps[b]) > 0; }); return ord; } int main() { int N; cin >> N; using T = Rational< int64_t >; using P = Point< T >; vector< P > ps; ps.reserve(N); vector< int64 > xx(N), yy(N); for(int i = 0; i < N; i++) { int64_t x, y; cin >> x >> y; ps.emplace_back(T(x), T(y)); xx[i] = x; yy[i] = y; } auto ord = arg_sort(ps); vector< int > X(N), Y(N); for(int i = 0; i < N; i++) { X[i] = xx[ord[i]]; Y[i] = yy[ord[i]]; } int ret = 0; for(int i = 0; i < N; i++) { auto dp = make_v< int >(N, 4); fill_v(dp, -inf); dp[i][0] = 0; for(int j = i; j < N; j++) { for(int k = j + 1; k < N; k++) { for(int l = 0; l < 3; l++) { chmax(dp[k][l + 1], dp[j][l] + X[j] * Y[k] - Y[j] * X[k]); } } chmax(ret,dp[j][3] + X[j] * Y[i] - Y[j] * X[i]); } } cout << ret << endl; }