#include <bits/stdc++.h>
using namespace std;
int main() {
	int n;
	cin>>n;
	int ans=0;
	int y;
	while(y!=495) {
		int x=n/100;
		int y=n/10%10;
		int z=n%10;//算出各位 
		int a=min(x,min(y,z));
		int b=max(x,max(y,z));
		int c=x+y+z-a-b;//算出最大最小 
		y=99*(b-a);//算出max-min 
		n=y;
		ans++;
	}
	cout<<ans;
}