Java program to user defined package

Write a program in Java to implement user defined package.

package mypack;
public class add {
    public int d1,d2;
    public add(int a ,int b) {
        d1=a;
        d2=b;
    }
    public void sum() {
        System.out.println("Sum of two given numbers is:" + (d1+d2) );
    }
}

import mypack.*;

class AddUse {
    public static void main(String[] args) {
        add  a = new add(10,20);
        a.sum();
    }
}

Output

Sum of two given numbers is : 30