我的代码：
```cpp
#include <bits/stdc++.h>
using namespace std;
long long n;
long long cnt;
long long s[30005];
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
while (cin >> n)
{
s[++cnt] = n;
}
long long ans = 0;
for (int i = 1; i <= cnt; i++)
{
ans += s[i];
}
ans *= (1 << cnt - 1);
cout << ans << endl;
return 0;
}
```
by coool @ 2023-08-25 11:19:31