[백준] P1110

import java.util.Scanner;

public class P1110 {

	public static void main(String[] args) {

		int n;
		int temp;
		int count = 0;
		int sum = 0;

		Scanner sc = new Scanner(System.in);

		n = sc.nextInt();

		temp = n;
		while (true) {

			if (n <= 9) {
				sum = n;

				n = sum * 10 + sum;
				count++;

			} else if (n >= 9) {

				sum = n / 10 + n % 10;

				n = (n % 10) * 10 + (sum % 10);

				count++;

			}

			if (temp == n) {
				break;
			}

		}
		System.out.println(count);

		sc.close();

	}

}