白駿1110

#include<iostream>

int main()
{
	int def;
	
	int one, ten;
	int tmp=0;
	std::cin >> def;

	if (def == 0)
	{
		std::cout << 1;
		return 0;
	}
	int count=0;
	if (def < 10)
		def *= 10;
	while (def!=tmp) {
		if (count == 0)
			tmp = def;
		one = tmp % 10;
		tmp = tmp / 10;
		ten = tmp % 10;
		tmp = one + ten;

		tmp = tmp % 10;
		tmp = one * 10 + tmp;
		
		count++;
	}
	
	std::cout << count;
	
}