#include <fstream>
#include <cstring>
#include <stack>
#include <bits/stdc++.h>
#include <vector>
#include <bitset>
#define rep(a,b,c) for(a = b; a <= c; ++a)
#define pob pop_back
#define pof pop_front
#define pub push_back
#define f first
#define s second
#define ll long long int
#define nmax 200001
#define mod 998244353
using namespace std;
ifstream fin("joc13.in");
ofstream fout("joc13.out");
int a[101][101], maximao = -1, n;

int main()
{
  int i, j;
  fin >> n;
  rep(i,1,n)
    {
      fin >> a[1][i];
      rep(j,1,i - 1)
       {
        if(a[1][j] != 0)
          a[j + 1][i] = min(a[1][i], a[1][j]) * (i - j);
        maximao = max(maximao, a[j + 1][i]);
        }

    }
  fout << maximao;
  return 0;
}