#include<cstdio>
#include<string>
#include<iostream>
#include<cmath>

using namespace std;

int main() {
    string str;

    while (getline(cin, str)) {
        int ans = 0;
        for (int i = 0 ; i < str.size(); i++) {

            ans += (str[i] - '0') * ( pow(2, (str.size() - i)) - 1);
        }
        printf("%d\n", ans);

    }

    return 0;
}