#include <bits/stdc++.h>
using namespace std;

int get_max(int x) {
    int a = x % 10, b = x % 100 / 10, c = x / 100;
    int Max = max({a, b, c});
    int Min = min({a, b, c});
    int Mid = a + b + c - Max - Min;
    return Max * 100 + Mid * 10 + Min;
}

int get_min(int x) {
    int a = x % 10, b = x % 100 / 10, c = x / 100;
    int Max = max({a, b, c});
    int Min = min({a, b, c});
    int Mid = a + b + c - Max - Min;
    return Min * 100 + Mid * 10 + Max;
}


int main() {
    int n;
    cin >> n;
    int cnt = 0; // 统计次数
    while (n != 495) {
        int a = get_max(n); // 获得最大值
        int b = get_min(n); // 获得最小值
        n = a - b;
        cnt++;
    }
    cout << cnt << endl;
}