//
// Will making this function tail-recursive help?
// No, the JVM stack will still go BOOM!
//

public class Factorial_Recursive
{
    public static void main( String[] args )
    {
        int argument = Integer.parseInt( args[0] );
        System.out.println( factorial(argument) ); 
    }

    public static int factorial( int n )
    {
        if ( n == 0 )
            return 1;
        else
            return n * factorial(n-1);
    }
}