//#define NDEBUG #include <cstddef> #include <cstdint> #include <vector> namespace n91 { using i8 = std::int_least8_t; using i32 = std::int_least32_t; using i64 = std::int_least64_t; using u8 = std::uint_least8_t; using u32 = std::uint_least32_t; using u64 = std::uint_least64_t; using isize = std::ptrdiff_t; using usize = std::size_t; class rep { const usize f, l; public: class itr { friend rep; usize i; constexpr itr(const usize x) noexcept : i(x) {} public: void operator++() noexcept { ++i; } constexpr usize operator*() const noexcept { return i; } constexpr bool operator!=(const itr x) const noexcept { return i != x.i; } }; constexpr rep(const usize first, const usize last) noexcept : f(first), l(last) {} constexpr itr begin() const noexcept { return itr(f); } constexpr itr end() const noexcept { return itr(l); } }; class revrep { const usize f, l; public: class itr { friend revrep; usize i; constexpr itr(usize x) noexcept : i(x) {} public: void operator++() noexcept { --i; } constexpr usize operator*() const noexcept { return i; } constexpr bool operator!=(const itr x) const noexcept { return i != x.i; } }; constexpr revrep(usize first, usize last) noexcept : f(--first), l(--last) {} constexpr itr begin() const noexcept { return itr(l); } constexpr itr end() const noexcept { return itr(f); } }; template <class T> using vec_alias = std::vector<T>; template <class T> auto md_vec(const usize n, const T &value) { return std::vector<T>(n, value); } template <class... Args> auto md_vec(const usize n, Args... args) { return std::vector<decltype(md_vec(args...))>(n, md_vec(args...)); } template <class T> constexpr T difference(const T &a, const T &b) { return a < b ? b - a : a - b; } } // namespace n91 #include <algorithm> #include <iostream> #include <utility> #include <cassert> #include <cstdint> namespace n91 { void main_() { usize n; std::cin >> n; struct item { u64 a, b; }; std::vector<item> is(n); for (auto &e : is) { std::cin >> e.a >> e.b; } std::sort(is.begin(), is.end(), [](const auto &l, const auto &r) {return r.b < l.b;}); static constexpr u64 INF = std::numeric_limits<u64>::max(); std::vector<u64> dp(n + 1, 0); const usize days = n - n / 3; for (const auto d : rep(0, days)) { u64 min = std::numeric_limits<u64>::max(); for (const auto i : rep(d, n)) { const u64 temp = dp[i] + is[i].a + is[i].b*d; dp[i] = min; min = std::min(min, temp); } dp[n] = min; } std::cout << dp.back() << std::endl; } } // namespace n91 int main() { n91::main_(); return 0; }