include <bits/stdc++.h>
using namespace std;
int main() {
int n, a, sum = 0;
cin >> n;
while (n > 0) {
a = n % 10;
if (a == 2 || a == 9 || a == 0 || a == 6) {
sum++;
}
if (a == 8) {
sum = sum + 2;
}
n = n / 10;
}
cout << sum;
return 0;
}