CrookedDigits

package com.company;


import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
	// write your code here
        Scanner sc = new Scanner(System.in);
        String digit = sc.nextLine();
        String number = digit.replace(".","");
        String Number = number.replace("-", "");


        int n = Integer.parseInt(Number);

        int sum =0;
        while (n > 0 || sum > 9)
        {
            if (n == 0) {
                n = sum;
                sum = 0;
            }
            sum += n % 10;
            n /= 10;
        }


        System.out.println(sum);

    }

    }