#include <iostream>

int main()
{
    using std::cout;

    /* This is a comment
    and it extends until the closing
    star-slash comment mark */
    cout << "Hello World!\n";
    //This comment ends at the end of this line!
    cout << "That comment ended\n";

    // double-slash comments cal also be alone on a line
    /* as can slas-star comments */
    return 0;
}