#include <iostream>

using namespace std;

int choice, x, y;

int fAddition(int a, int b) {
    int c = a + b;
    return(c);
}

int fSubtraction(int a, int b) {
    int c = a - b;
    return(c);
}

int fMultiplication(int a, int b) {
    int c = a * b;
    return(c);
}

int fDivision(int a, int b) {
    if (b == 0) {
        return(42);
    }

    else {
        int c = a / b;
        return(c);
    }
}

int main() {
    int loop = 1;
    while (loop == 1) {
        cout << "\n Make a choice:" << endl;
        cout << "  1: Addition" << endl;
        cout << "  2: Subtraction" << endl;
        cout << "  3: Multiplication" << endl;
        cout << "  4: Division" << endl;
        cout << "  5: Quit" << endl;
        cout << " > ";
        cin >> choice;
        cout << endl;
        switch (choice) {
            case 1:
                cout << " Two numbers: ";
                cin >> x >> y;
                cout << " The result is: " << fAddition(x, y) << endl;
                break;
            case 2:
                cout << " Two numbers: ";
                cin >> x >> y;
                cout << " The result is: " << fSubtraction(x, y) << endl;
                break;
            case 3:
                cout << " Two numbers: ";
                cin >> x >> y;
                cout << " The result is: " << fMultiplication(x, y) << endl;
                break;
            case 4:
                cout << " Two numbers: ";
                cin >> x >> y;
                cout << " The result is: " << fDivision(x, y) << endl;
                break;
            case 5:
                loop = 0;
                break;
            default:
                cout << " That's not a valid option" << endl;
        }
    }
    return 0;
}