#include <bits/stdc++.h> using namespace std; int main(){ long long n , m , ans; cin >> n; ans = 0; for (int i = 1 ; i <= 4 ; ++i){ int x = n % 10; n /= 10; if (x == 0) ans += 1; if (x == 4) ans += 1; if (x == 6) ans += 1; if (x == 8) ans += 2; if (x == 9) ans += 1; } cout << ans; return 0; }