#include <bits/stdc++.h>
#define endl "\n"
using namespace std;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n;
	long long sum = 0;
	long long t;
	while (cin >> t)
	{
		n++;
		sum += t;
	}
	cout << (long long)(sum * (pow(2, n - 1))) << endl;
	return 0;
}

最后一个点A，其他全部W