#include <bits/stdc++.h>
using namespace std;
const long long INF = 100000000000;
int main(){
  int N;
  cin >> N;
  vector<long long> A(N);
  for (int i = 0; i < N; i++){
    cin >> A[i];
  }
  vector<long long> dp(N + 1, 0);
  for (int i = 0; i < N; i++){
    long long mx = -INF;
    for (int j = i; j < N; j++){
      mx = max(mx, A[j]);
      dp[j + 1] = max(dp[j + 1], dp[i] + (long long) abs(mx) * (j - i + 1));
    }
  }
  cout << dp[N] << endl;
}