#include <bits/stdc++.h>

using namespace std;

int solve(vector <int> A) {
    int t = A.size();
    
    int n = (t*t + t)/2;
    n = (n*n + n)/2;
    
    int s = A[0] * n;
    
    for(int i = 1; i < A.size(); ++i)
    {
        s -= (A[0] - A[i]) * (A.size() >> (i - 1));
    }
    return s;
}

int main() {
    int n;
    cin >> n;
    vector<int> A(n);
    for(int a_i = 0; a_i < n; a_i++){
       cin >> A[a_i];
    }
    int result = solve(A);
    cout << result << endl;
    return 0;
}