Solution for test question

public class Main {
    public static void main(String[] args)
    {
        Scanner UI = new Scanner(System.in);
        String save = "";
        int last = -1;
        System.out.println("Enter number");
        int userNum = UI.nextInt();
        while(last < userNum)
        {
            save += userNum + ", ";
            System.out.println("Enter number that is bigger than last");
            last = userNum;
            userNum = UI.nextInt();

        }
        System.out.println(save);
    }
}