#include<cstdio>
#include<string>
#include<math.h>
using namespace std;


int main(){
    char arr[100];
   while( scanf("%s",arr) != EOF){
        string buf = arr;
        int totalsum = 0;
        for (unsigned i = 0; i < buf.size(); ++i) {
            int num = buf[i] - '0';
            totalsum = totalsum + num * (pow(2,buf.size()-i) - 1);
        }
        printf("%d\n",totalsum);
     
    }

}