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;

}