#include<bits/stdc++.h>
using namespace std;
int main(){
    int a,e,f,g,h,i,j,qq;
    cin>>a;
    while(a!=495){
        e=max(a/100,max(a%100/10,a%10));
        g=min(a/100,min(a%100/10,a%10));
        f=a/100+a%100/10+a%10-e-g;
        h=e*100+f*10+g;
        i=g*100+f*10+e;
        a=h-i;
        qq++;
    }
    cout<<qq<<endl;
}