575 - Skew Binary

#include<stdio.h>
#include<string.h>
#include<math.h>
int main()
{
    char skem[100];
    int k = 0;
    long sum = 0;
    //freopen("in.txt","r",stdin);
    while(gets(skem))
    {
        int n = strlen(skem);
        int num = skem[0]-'0';
        if(n==1 && num == 0) break;
        for(int i=0;i<n;i++)
        {
            k=n-i;
            sum += ((skem[i]-'0')*((long)pow(2,k)-1));
        }
        printf("%ld\n",sum);
        sum = 0;
    }
    return 0;
}