#include <iostream>
using namespace std;
int main(void)
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int N, A, B, count = 0, temp;
cin >> N;
temp = N;
while (1)
{
if (temp < 10)
{
A = 0;
B = temp;
temp = (B * 10) + (A + B);
}
else
{
A = temp / 10;
B = temp % 10;
temp = (B * 10) + ((A + B) % 10);
}
count++;
if (temp == N)
{
break;
}
else
{
;
}
}
cout << count << "\n";
return 0;
}