Identify a number is well ordered or not ?

Note- A number is well ordered if all digits are in ascending order ex- 123456789.
Not well ordered number - ex- 2341 (because here 1 is coming after 4 so it is not well ordered.)


Code-

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;

public class NumWellOrbered {
    public static void main(String[] args) {
        System.out.print("Enter a number: ");
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int r=0, s=n, j=0;
        List<Integer> num = new ArrayList<Integer>();
        while(s!=0){
            r = s%10;
            s = s/10;
            num.add(r);
        }
       
        for(j=(num.size()-1); j>0; j--){
            if(num.get(j)>num.get(j-1)){
                System.out.println("Number "+n+" is not well ordered");
                break;
            }
        }
        if(j==0){
            System.out.println("Number "+n+" is well ordered");
        }
    }
}


Output 1-
Enter a number: 5436
Number 5436 is not well ordered

Output 2-
Enter a number: 456789
Number 456789 is well ordered