public class Choose{
    static long factorial(int n){
        long result;
        if (n>0) 
            result=n*factorial(n-1);
        else
            result=1;

        Assert.check(result>0, "positive result");
        return result;
    }

    static long choose(int n, int r){
        return factorial(n)/(factorial(r)*factorial(n-r));
    }


    public static void main(String[] args){
        
        long result=choose(50,2);

        System.out.println(factorial(50));
        
        System.out.println(result);
        

    }
}