#include <bits/stdc++.h> using namespace std; using lint = long long; template<class T = int> using V = vector<T>; template<class T = int> using VV = V< V<T> >; int main() { cin.tie(nullptr); ios::sync_with_stdio(false); int n; cin >> n; V<lint> a(n), b(n); for (int i = 0; i < n; ++i) cin >> a[i] >> b[i]; V<> idx(n); iota(begin(idx), end(idx), 0); sort(begin(idx), end(idx), [&](int i, int j) { return b[i] > b[j]; }); V<lint> dp(n / 3 + 1, 9e18); dp[0] = 0; for (int i = 0; i < n; ++i) { V<lint> ndp(n / 3 + 1, 9e18); for (int x = 0; x <= n / 3; ++x) { ndp[x] = min(ndp[x], dp[x] + a[idx[i]] + b[idx[i]] * (i - x)); if (x) ndp[x] = min(ndp[x], dp[x - 1]); } swap(dp, ndp); } cout << dp.back() << '\n'; }