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