#include <iostream>
using namespace std;
int main(void)
{
int N = 0;
int count = 0;
int quote = 0;
int remain = 0;
int sum = 0;
int newNumber = 0;
int tempN = 0;
cin >> N;
if (N>=0 and N<=99)
{
tempN = N;
while (true)
{
quote = tempN / 10; //2, 6, 8, 4
remain = tempN % 10; // 6, 8, 4, 2
sum = quote + remain; // 8, 14, 12, 6
if (sum <10)
{
sum = (sum * 10) + sum;
}
tempN = (remain * 10) + (sum % 10); // 8, 84, 42, 2
count = count + 1; // 1, 2, 3, 4
if (N == tempN)
{
cout << count << '\n';
break;
}
}
}
return 0;
}