cf 102B

#include<iostream>
#include<algorithm>

using namespace std;

int func(int n)
{
    int sm = 0;
    while(n > 0)
    {
        sm += n % 10;
        n /= 10;
    }
    return sm;
}

int main()
{
    string s;
    cin >> s;

    if(s.length() == 1)
    {
        printf("0\n");
        return 0;
    }

    int i, sum = 0, c = 1;
    for(i = 0; i < s.length(); i++)
    {
        sum += (s[i] - '0');
    }
    //cout << sum << endl;
    while(sum >= 10)
    {
        sum = func(sum);
        c++;
        //cout << ans << endl;
    }
    //cout << sum << endl;

    printf("%d\n", c);
}