DigitRoots

import java.util.Scanner;

public class Root {

	private static int sum( int a )
	{
		int ans = 0;
		while( a != 0 )
		{
			ans += a%10;
			a /= 10;
		}
		return ans;
	}

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		int N = scan.nextInt();
		while (N != 0) {
			while( N >= 10 )
			{
				N = sum(N);
			}
			System.out.println("Digital Root: " + N);
			N = scan.nextInt();
		}

		scan.close();

	}

}