#include <bits/stdc++.h>
using namespace std;
int f(int now)
{
    int a = now % 10;
    int b = now / 10 % 10;
    int c = now / 100 % 10;
    int x, y; // x 存最大的、y 存最小的
    if (b > a)
        swap(a, b);
    if (c > a)
        swap(a, c);
    if (c > b)
        swap(b, c);
    x = a * 100 + b * 10 + c;
    y = c * 100 + b * 10 + a;
    return x - y;
}
int main()
{
    int n;
    cin >> n;
    int ans = 0;
    while (n != 495)
    {
        ans++;
        n = f(n);
    }
    cout << ans;
    return 0;
}