func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     unsigned long long a, b;     cin >> a >> b;     while (a != 0 && b != 0) {       if (a >= 2 * b) {         a = a % (2 * b);       } else if (b >= 2 * a) {         b = b % (a * 2);       } else         break;     }     cout << a <<     << b << endl;     return 0;   }   