#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,cnt=0;
    cin>>n;
    while(n!=495)
    {
        int g=n%10;
        int s=n/10%10;
        int b=n/100;
        if(g>s)
        {
            int temp=g;
            g=s;
            s=temp;
        }
        if(s>b)
        {
            int temp=s;
            s=b;
            b=temp;
        }
        if(g>s)
        {
            int temp=g;
            g=s;
            s=temp;
        }
        int M=g+s*10+b*100;
        int m=b+s*10+g*100;
        n=M-m;
        cnt++;
    }
    cout<<cnt;
    return 0;
}