// CPP program to illustrate
// undefined behavior of
// gcd function of C++ STL
#include <iostream>
#include <algorithm>
// #include<numeric> for C++17
using namespace std;
int main()
{
cout << "gcd(6, 20) = " << __gcd(2.0, 8) << endl; // gcd(2.0,8) for C++17
}