text: #include <iostream>
  
  constexpr int gcd(int a, int b)
  {
      while (b != 0)
      {
          auto t = b;
          b = a % b;
          a = t;
      }
      return a;
  }
  
  int main()
  {
  
      std::cout << std::endl;
  
      constexpr auto res = gcd(100, 10);
      std::cout << "gcd(100, 10) " << res << std::endl;
  
      auto val = 100;
      auto res2 = gcd(val, 10);
      std::cout << "gcd(val, 10) " << res2 << std::endl;
      std::cin.get();
      return 0;
  }