#include #include #include #include #include template inline bool chmin(T &lhs, const U &rhs) { if (lhs > rhs) { lhs = rhs; return true; } return false; } template inline bool chmax(T &lhs, const U &rhs) { if (lhs < rhs) { lhs = rhs; return true; } return false; } // [l, r) from l to r struct range { struct itr { int i; constexpr itr(int i_): i(i_) { } constexpr void operator ++ () { ++i; } constexpr int operator * () const { return i; } constexpr bool operator != (itr x) const { return i != x.i; } }; const itr l, r; constexpr range(int l_, int r_): l(l_), r(std::max(l_, r_)) { } constexpr itr begin() const { return l; } constexpr itr end() const { return r; } }; // [l, r) from r to l struct revrange { struct itr { int i; constexpr itr(int i_): i(i_) { } constexpr void operator ++ () { --i; } constexpr int operator * () const { return i; } constexpr bool operator != (itr x) const { return i != x.i; } }; const itr l, r; constexpr revrange(int l_, int r_): l(l_ - 1), r(std::max(l_, r_) - 1) { } constexpr itr begin() const { return r; } constexpr itr end() const { return l; } }; int main() { int N; std::cin >> N; std::vector X(N), Y(N); for (int i: range(0, N)) { std::cin >> X[i] >> Y[i]; } int ans = 0; for (int i: range(0, N)) { for (int j: range(0, i)) { int x = X[i] - X[j], y = Y[i] - Y[j]; int cnt = 0; for (int k: range(0, N)) { // if (k == i || k == j) { // continue; // } int tx = X[i] - X[k], ty = Y[i] - Y[k]; if (tx * y == x * ty) { ++cnt; } } chmax(ans, cnt); } } std::cout << ans << '\n'; return 0; }