#include <bits/stdc++.h>
using namespace std;
int N;
int A[200];
int K;
int main() {
  cin >> N;
  for (int i = 0; i < N; i++) cin >> A[i];
  K = 0;
  for (int i = 0; i < N; i++) {
    K = max(K, A[i]);
  }
  int T = 0;
  for (int i = 0; i < N; i++) {
    T += A[i];
  }
  T = 2 * T + 1;
  K = max(K, (T + N - 1) / N);
  cout << K << '\n';
  return 0;
}
