#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
const int N=1e5+10;
int h[N];
int main()
{
int n;
cin>>n;
for(int i=0;i<n;i++)cin>>h[i];
int l=0,r=n-1;
int res=0;
while(l<r){
res=max(res,(r-l)*min(h[r],h[l]));
if(h[l]<h[r])l++;
else r--;
}
cout<<res<<endl;
return 0;
}