#include <iostream>

using namespace std;

int main()
{
    // korisnikot ni vnesuva ocena, i treba da ispecatime opisna ocena
    char ocenka;
    cin >> ocenka;
    //int, char
    switch(ocenka){
        case 'F':
            cout << "nedovolen" << endl;
        case 'D':
            cout << "dovolen" << endl;
        case 'C':
            cout << "dobar" << endl;
        case 'B':
            cout << "mnogu dobar" << endl;
        case 'A':
            cout << "odlicen" << endl;
        default:
            cout << "ne postoi ovaa ocenka" << endl;
    }


    return 0;
}