// file Product.java

public class Product extends ExpTree {

   public Product(ExpTree[] c) {
       super(c);
     }

   public Object evaluate() {
       int product= 1;
       for (int i=0; i<getChildren().length; i++) 
          product = product * (int) getChildren()[i].evaluate();
       return (Integer) product;
     }

   public String display() {
       String s = "(" + getChildren()[0].display();
       for (int i=1; i<getChildren().length; i++) 
          s = s + " * " + getChildren()[i].display();
       return s + ")";
     }
}