Sum of the digits: An intriguing Recursion program

import java.util.*;
class Recur
{
    int sum=0;
    int sumofdigits(int num)
    { 
        if(num>0)
        {
            int r=num%10;
            sum+=r;
            sumofdigits(num/10);
        }
        return sum;
    } 
    public static void main()
    {
        Scanner sc=new Scanner(System.in);
        System.out.println("Enter a number to print the sum of the digits");
        int n=sc.nextInt();
        Recur obj=new Recur();
        System.out.println("The sum of the digits is "+ obj.sumofdigits(n));   
    }
}