请写出程序的运行结果。public class E {public static void main(String[] args) {Student stu = new Student();Com com = stu;int m = com.add(1,20);People p = stu;int n=p.add(1, 20);System.out.printf("%d:%d", m,n);}}intece Com{int add(int a,int b);}abstract class People{abstract int add(int a,int b);}class Student extends People implements Com{public int add(int a,int b) {return a+b;}}