abstract class SuperClass
{
	abstract int display();
}
class SubClassA extends SuperClass
{
	private int n;
	public SubClassA (int n){
       this.n=n;
	}
	public int display(){
		return (1+n)*n/2;
	}
}
class SubClassB extends SuperClass
{
	private int n;
	public  SubClassB (int n){
		this.n=n;
	}
	public int display(){
	      int ji=1;
		 int i;
		for (i=1;i<=n ;i++ )
		{
			ji*=i;
		}
        return ji;
	}
}
 public class PolyTesster
{
    public static void main(String args[])
	{ 
		SuperClass array[]=new SuperClass[2];
			array[0]=new SubClassA(6);
            array[1]=new SubClassB(6);
			for (int in=1;in<2;in++ ){
	            System.out.println("這是和"+array[0].display());
		        System.out.println("這是積"+array[1].display());          
	        }
	   
	}
}