575 - Skew Binary

/***

            Bismillahir Rahmanir Rahim
            Read the name of Allah, who created you!!!
            Author : Shah Newaj Rabbi Shishir
            Department of CSE, City University, Bangladesh.

***/

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

#define sf scanf
#define pf printf
#define scase sf ("%d",&tc)
#define sn sf ("%d",&n)
#define whilecase while (tc--)
#define eof while (cin >> n)
#define forloop for (pos=1; pos<=tc; pos++)
#define arrayloop (i=0; i<n; i++)
#define cinstr cin >> str
#define getstr getline (cin,str)
#define pcase pf ("Case %d: ",pos)
#define pb push_back
#define in insert
#define llu unsigned long long
#define lld long long
#define u unsigned int

int main (void)
{
    string str;
    int len,i,dec,k;

    while (cin >> str)
    {
        if (str == "0")
            break;

        k = len = str.size();
        dec = 0;

        for (i=0; i<len; i++)
            dec += (str[i]-'0') * (pow(2,k--) - 1);

        cout << dec << endl;
    }

    return 0;
}