#include <iostream>
using namespace std;
int num,a,b,c,d=0;

int f(int x){
    a,b,c,d=0;
    if(x==495){
    	return num;
	}
    
    a=x/100;
    b=x/10%10;
    c=x%10;
    
    d=a+b+c;
    int aa=a;
    a=max(max(a,b),c);
    
    c=min(min(aa,b),c);
    b=d-a-c;
    
    aa=a;
    a=a*100+b*10+c;
    b=c*100+b*10+aa;
  
    x=a-b;
	num++;
	f(x);
}

int main(){
    int n;
    cin>>n;
    cout<<f(n);
   
	return 0;
}