#include<bits/stdc++.h>
using namespace std;

int main() {
    string s;
    cin>>s;
    unordered_map<int,int>p;
    p['0']=p['6']=p['9']=1;
    p['8']=2;
    int ans=0;
    for(char& c:s){
        ans+=p[c];
    }
    cout<<ans;
}