func_code_string: #include <bits/stdc++.h>   using namespace std;   char s[200222];   int main() {     while (scanf( %s , s) > 0) {       int n = strlen(s);       int a, b, c;       a = b = c = 0;       for (int i = 0; i < n; i++) {         if (s[i] ==  0 )           a++;         else if (s[i] ==  1 )           b++;       }       int fst = (n - 1) / 2;       int snd = (n - 2) / 2;       if (b <= fst) puts( 00 );       if (a <= snd + 1 && b + (s[n - 1] ==  ? ) <= fst + 1 && s[n - 1] !=  0 )         puts( 01 );       if (b <= fst + 1 && a + (s[n - 1] ==  ? ) <= snd + 1 && s[n - 1] !=  1 )         puts( 10 );       if (a <= snd) puts( 11 );     }     return 0;   }   