求调，，谢谢！

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

int main()
{
    long long sum=0;
    long long number=0,i;
    while(cin>>i)
    {
        sum+=i;
        number++;
    }
    printf("%lld",sum*pow(2,number-1));
    return 0;
}