cpp_chief_hopper

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;


int main() {
    // insert code here...
    queue<int> overflow;
    int T, stkCnt=0;
    cin >> T;
    int A[100000];
    int max = 0;
    for(int i=0; i<T; i++){
        cin >> A[i];
        //A[i] = 2;
        if(A[i]>max)
            max = A[i];
    }
    //A[20]=1;
    long long int e=0;
    for(int n=0;n<=max;n++){
        e = n;
        int i=0;
        while(i < T ){
            e = 2*e - A[i];
            if(stkCnt > 0){
                overflow.push(2);
                for(int i=0; i< stkCnt ;i++){
                    do{
                        int num = overflow.front();
                        overflow.pop();
                        overflow.push(num);
                    }while(overflow.front() == 2);
                    overflow.push(2);
                }
            }
            if(e > 1000000000){
                overflow.push(999900000);
                e = e - 999900000;
                stkCnt++;
            }
            int num = 1;
            if(e < 0 && stkCnt > 0){
                do{
                    num = num * overflow.front();
                    overflow.pop();
                }while(overflow.front()==2);
                e = e + num;
            }
            if(e<0) break;
            i++;
        }
        if(i == T){
            e = n;
            break;
        }
    }
    cout << e << endl;
    return 0;
}