#include <iostream>
using namespace std;
//按题目要求
int main() {
    string s;cin>>s;
    int sum=0;
    for(int i=0;i<s.size();i++){
        if(s[i]=='0'||s[i]=='6'||s[i]=='9')sum++;
        else if(s[i]=='8')sum+=2;
    }
    cout<<sum;
}