#include <bits/stdc++.h>
#define ll long long
#define endl "\n"
using namespace std;
 
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
 
    string s;
    cin >> s;
    if (s.length() == 1)
    {
        cout << 0 << endl;
        return 0;
    }
    int cnt = 0;
    while (s.length() > 1)
    {
        int sum = 0;
        for (int i = 0; i < s.size(); i++)
        {
            sum += s[i] - '0';
        }
        s = to_string(sum);
        cnt++;
    }
    cout << cnt << endl;
 
    return 0;
}
 

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