#include<bits/stdc++.h>
using namespace std;
int main() {    
    int a,b,aa=0;
    cin>>a;
    b=a;
    int d[3];
    while(a!=495){
    
        for(int i=0;i<=3;i++){
            
            d[i]=b%10;
            b=b/10;}
        sort(d, d + 2);
        a = (d[2] * 100 + d[1] * 10 + d[0]) - (d[0] * 100 + d[1] * 10 + d[2]);
        aa++;
        }


       
    cout<<aa;
    return 0;
}