#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
#define rep(i, s, t) for (ll i = s; i < (ll)(t); i++)
#define all(x) begin(x), end(x)

template <class T> bool chmin(T& x, T y) {
	return x > y ? (x = y, true) : false;
}
template <class T> bool chmax(T& x, T y) {
	return x < y ? (x = y, true) : false;
}

struct io_setup {
	io_setup() {
		ios::sync_with_stdio(false);
		cin.tie(nullptr);
		cout << fixed << setprecision(15);
	}
} io_setup;

void solve() {
	int n;
	cin >> n;
	vector<int> a(n), b(n);
	rep(i, 0, n) cin >> a[i] >> b[i];
	reverse(a.begin(), a.end());
	reverse(b.begin(), b.end());
	vector<ll> dp(1, 0);
	rep(i, 0, n) {
		vector<ll> ndp(i + 2, -1);
		rep(j, 0, i + 1) {
			if (dp[j] == -1) continue;
			chmax(ndp[j], dp[j] + a[i] * j);
			chmax(ndp[j + 1], dp[j] + b[i]);
		}
		swap(dp, ndp);
	}
	cout << ranges::max(dp) << '\n';
}

int main() {
	int t = 1;
	// cin >> t;
	while (t--) solve();
}