#A. 小可的圆圈数数

#include<bits/stdc++.h>
using namespace std;
int cnt;
int main()
{
	string s;
	cin>>s;
	for(int i = 0;i < s.size();i++)
	{
			if(s[i] == '0' || s[i] == '6' || s[i] == '9'){
			cnt++;
		}
		if(s[i] == '8')
		{
			cnt+=2;
		}
	}
	cout<<cnt;
 }