#include <bits/stdc++.h>   using namespace std;   int main() {     string aux;     cin >> aux;     int flag_Invalid_Input = 0;     int memo[10] = {1, 2, 4, 8, 16, 32, 64, 128, 256, 512};     int counter = 0;     int len = aux.size();     int i, j;     for (i = 0; i < len; i++) {       if (aux[i] >  1 ) {         for (j = 0; j < len - i; j++) {           counter += memo[j];         }         break;       }       if (aux[i] ==  1 ) {         counter += memo[len - i - 1];       }     }     cout << counter;   }   