Java Progarm to accept the name, class, roll no and 3 subject marks and display all the details with total and average marks

import java.util.*;
public class Mark{
    Scanner scan=new Scanner(System.in);
    int rollNo, clas;
    String name;
    float mark1, mark2, mark3, total, average;
    public void input(){
        try{
            System.out.println("Enter the Name of the Student: ");
            name=scan.nextLine();
        }
        catch(Exception e){
            System.out.println("Error Code: "+e);
            System.exit(0);
        }
        try{
            System.out.println("Enter "+name+"'s Class: ");
            clas=scan.nextInt();
            System.out.println("Enter "+name+"'s Roll No: ");
            rollNo=scan.nextInt();
            System.out.println("Enter 1^st Subject Marks: ");
            mark1=scan.nextFloat();
            System.out.println("Enter 2^nd Subject Marks: ");
            mark2=scan.nextFloat();
            System.out.println("Enter 3^rd Subject Marks: ");
            mark3=scan.nextFloat();
        }
        catch(NumberFormatException E){
            System.out.println("Error Code: "+E);
            System.exit(0);
        }
    }

    public void compute(){
        total=mark1+mark2+mark3;
        average=total/3;
    }

    public void details(){
        System.out.println("\n\nDetails you entered:- ");
        System.out.println("Name: "+name);
        System.out.println("Class: "+clas);
        System.out.println("Roll No: "+rollNo);
        System.out.println("1^st Subject Marks: "+mark1+"\n2^nd Subject Marks: "+mark2+"\n3^rd Subject Marks: "+mark3);
        System.out.println("Total: "+total+"\nAverage: "+average);
    }

    public static void main(String[] args){
        Mark details=new Mark();
        details.input();
        details.compute();
        details.details();
    }
}

Output:-
Enter the Name of the Student:
Jean
Enter Jean's Class:
10
Enter Jean's Roll No:
08
Enter 1st Subject Marks:
89
Enter 2nd Subject Marks:
87
Enter 3rd Subject Marks:
79

Details you entered:-
Name: Jean
Class: 10
Roll No: 8
1st Subject Marks: 89.0
2nd Subject Marks: 87.0
3rd Subject Marks: 79.0
Total: 255.0
Average: 85.0