#include <bits/stdc++.h>
using namespace std;

signed main(){
  int N; cin >> N;
  vector< int > A( N );
  for( int i = 0; i < N; ++i )
    cin >> A[ i ];
  int sum = 0;
  for( int i = 0; i < N; ++i )
    sum += A[ i ];
  int cnt = 0;
  for( int i = 0; i < N; ++i )
    sum += A[ i ] * 10 <= sum;
  cout << cnt * 30 << endl;
  return 0;
}