#include <stdio.h>

void main()
{
	int input, change, count = 0;
	do
	{
		scanf("%d", &input);
		change = input;
	} while (input < -1 || input > 100);

	do
	{
		int sum = change / 10 + change % 10;
		change = (change % 10) * 10 + (sum % 10);
		count++;
	} while (input != change);

	printf("%d", count);
}