#include <bits/stdc++.h>
using namespace std;
const int N = 10;
int a[N];
int main() {
    int n;
    cin >> n;
    int cnt = 0;
    while (true) {
        cnt++;
        a[1] = n / 100;
        a[2] = n % 100 / 10;
        a[3] = n % 10;
        sort(a + 1, a + 1 + 3);
        int mx = a[3] * 100 + a[2] * 10 + a[1];
        int mi = a[1] * 100 + a[2] * 10 + a[3];
        n = mx - mi;
        if (n == 495) break;
    }
    cout << cnt << endl;
    return 0;
}