#include <iostream>
// for toupper
#include <cctype>

using namespace std;

int main()
{
    char grade;

    cout << "Please enter your grade: ";
    cin >> grade;

    grade = toupper(grade);

    switch (grade)
    {
        case 'A':
            cout << "Good and excellent job!!!!!!!!!!" << endl;
        case 'B':
            cout << "Good job, not bad, go for the A next time." << endl;
        case 'C':
            cout << "Ok, average, work harder!" << endl;
            break;
        case 'D':
            cout << "Slacker!!!" << endl;
            cout << "(At least you're not failing.)" << endl;
            break;
        case 'F':
            cout << "Good heavens, you're horrible." << endl;
            break;
        default:
            cout << "Invalid grade entered." << endl;
            exit(1);
    }

    return 0;
}