#include<string>
#include<iostream>
#include<cstdio>
#include<vector>
#include<algorithm>
#include<functional>
using namespace std;
typedef long long int llint;
#define  pub push_back

//A
//BABA
int main(void){
	string n;
	int i,ans=0,ana=0;
	cin>>n;
	for(i=0;i<n.size();i++){
		switch(n[i]){
		case '8':
			ana++;
		case '0':case '4':case '6':case '9':
			ana++;
		}
	}
	ans=min(1+ana+n.size()*2,n.size()+ana*2+2);
	cout<<ans<<endl;
	return 0;
}