下面这个能过，但是改成注释就会 WA

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int a[35],n=1;
ll sum;

int main(){
	while(scanf("%d",&a[n])!=EOF){
		a[n]+=a[n-1];
		n++;
	}
//      while(scanf("%d",&a[++n])!=EOF)a[n]+=a[n-1];
	printf("%lld",(1LL<<n-2)*a[n-1]);
	return 0;
}