#include <bits/stdc++.h>
using namespace std;
#define ALL(x) (x).begin(), (x).end()
#define REP(i,n) for(int i=0; i<n; i++)
bool chmax(auto& a, auto b) { return a<b ? a=b, true : false; }
bool chmin(auto& a, auto b) { return a>b ? a=b, true : false; }
using ll=long long; const int INF=1e9+10; const ll INFL=4e18;

#ifdef DEBUG
#include "./debug.hpp"
#else
#define debug(...)
#define print_line
#endif

//----------------------------------------------------------

void solve() {
    ll N; cin>>N;
    vector<ll> A(N), B(N);
    REP(i,N) cin>>A[i]>>B[i];
    
    vector<ll> dp(N+1,0), ndp=dp;
    dp[0]=0;

    REP(i,N) {
        fill(ALL(ndp),-INFL);
        for(int j=0; j<=N-i; j++) {
            chmax(ndp[j],dp[j]+A[i]*j);
            if(j>0) chmax(ndp[j-1],dp[j]+B[i]);
        }
        swap(dp,ndp);
    }

    cout<<dp[0]<<endl;
}

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    //cout<<fixed<<setprecision(15);
    int T=1; //cin>>T;
    while(T--) solve();
}