#include<bits/stdc++.h>
using namespace std;

int main(){
  using ll=long long;
  ll inf=1e18;
  int n;
  cin>>n;
  vector<ll> a(n),b(n);
  for (int i=0;i<n;i++) cin>>a[i]>>b[i];
  reverse(a.begin(),a.end());
  reverse(b.begin(),b.end());
  vector dp(n+1,vector<ll>(n+1,-inf));
  dp[0][0]=0;
  for (int i=0;i<n;i++){
    for (int j=0;j<=n;j++){
      dp[i+1][j]=max(dp[i+1][j],dp[i][j]+a[i]*j);
      if (j+1<=n) dp[i+1][j+1]=max(dp[i+1][j+1],dp[i][j]+b[i]);
    }
  }
  ll ans=*max_element(dp[n].begin(),dp[n].end());
  cout<<ans<<endl;
}