POJ 1565 Skew Binary G++

#include <iostream>
#include <string>
using namespace std;
int main()
{
	while(1)
	{
		string s;
		cin>>s;
		if(s=="0")
		{
			break;
		}
		long long sum=0;
		long long base=2;
		for(int i=s.size()-1;i>=0;i--)
		{
			sum=sum+(long long)(s[i]-'0')*(base-1);
			base=base*2;
		}
		cout<<sum<<endl;
	}
	return 0;
}