#include <bits/stdc++.h>   using namespace std;   int main() {     string str;     cin >> str;     int count = 0;     while (str.size() > 1) {       string temp;       int num = 0;       count++;       for (int i = 0; i < str.size(); i++) {         num += str[i] - 48;       }       str =   ;       str = to_string(num);     }     cout << count << endl;     return 0;   }   