#include <bits/stdc++.h>
using namespace std;
using ll=long long;
int main(){
	int n;
	cin>>n;
	vector<ll> a(n),b(n);
	for(int i=0;i<n;i++)cin>>a[i]>>b[i];
	vector<ll> crt(n+1,-1);
	crt[0]=0;
	for(int i=n-1;i>=0;i--){
		vector<ll> nxt(n+1,-1);
		for(int j=0;j<n;j++){
			if(crt[j]==-1)continue;
			nxt[j]=max(nxt[j],crt[j]+a[i]*j);
			nxt[j+1]=max(nxt[j+1],crt[j]+b[i]);
		}
		swap(nxt,crt);
	}
	ll ans=0;
	for(int i=0;i<=n;i++)ans=max(ans,crt[i]);
	cout<<ans<<endl;
}