Creating marklist In Java

import java.io.*;
public class Stud1{
private int mark1,mark2,mark3,result;
private float per;
private String name;
public Stud1(String name,int mark1,int mark2,int mark3){
this.name=name;
this.mark1=mark1;
this.mark2=mark2;
this.mark3=mark3;
}
public void calculate(){
result=mark1+mark2+mark3;
per=(float)result/300*100;
System.out.println("Name Of Student : "+this.name);
System.out.println("Result : "+result);
System.out.println("Percentage : "+per);
}
public static void main(String args[]){
Stud1 s=new Stud1("Avinash",79,78,79);
s.calculate();
Demo2 n= new Demo2();
n.defBelong();
}
}