#include <bits/stdc++.h>
using namespace std;
int fanshu(int i){
	int n=0,t=0,o=1;
	string s;
	for(;o<i;o*=10){
		s[n]=i/o%10+'0';
		n++;
	}
	for(int y=0;y<n;y++){
		o/=10;
		t+=(s[y]-'0')*o;
	}
	return t;
}
int main(){
	int i;
	cin>>i;
	for(int y=0;;y++){
		if(i==fanshu(i)){
			cout<<y;
			return 0;
		}
		i+=fanshu(i);
	}
	return 0;
}

/**************************************************************
	Problem: 1083
	User: zhouhongyi
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/