#include <iostream>
using namespace std;
int n;
int a[200000];
int s(int l, int r) {
  int i;
  int x = 0;
  for (i=l; i<=r; i++) x += a[i];
  return x;
}
int main() {
  int i,j;

  cin >> n;
  for (i=0; i<n; i++) cin >> a[i];

  int sum = 0;
  for (i=0; i<n; i++)
    for (j=i; j<n; j++)
      sum += s(i, j);
  cout << sum;
  return 0;
}