#include<bits/stdc++.h>
using namespace std;
int main() {    
    int num,a,b,c,d,e,f,aa=0;
    cin>>num;
    while(num!=495){
        

        a=num%10;
        b=num/10%10;
        c=num/100%10;
        if(c<b){
			e=b;
			b=c;
			c=e;
		}
		if(b<a){
			e=b;
			b=a;
			a=e;
		}if(c<b){
			e=c;
			c=b;
			b=e;
		}
        d=a*100+b*10+c*1;
        f=a+b*10+c*100;
        num=d-f;
        aa++;
        if(num==495){
            break;}}
        
       
    cout<<aa;
    return 0;
}