func_code_string: #include <bits/stdc++.h>   int main() {     int a;     scanf( %d , &a);     int n = 7, i = 1, sum = 0, k = 1;     while (a) {       int num = a % 10;       if (num == 4)         sum += 1 * k;       else         sum += 2 * k;       a /= 10;       i++;       k *= 2;     }     printf( %d , sum);   }   