Write a menu driven program to access a number from the user and check whether it is a BUZZ number or to accept any two numbers and to print the GCD of them.

1. A BUZZ number is the number which either ends with 7 or is divisible by 7.
2. GCD (Greatest Common Divisor) of two integers is calculated by continued division method. Divide the larger number by the smaller; the remainder then divides the previous divisor. The process is repeated till the remainder is zero. The divisor then results the GCD.

import java.util.Scanner;

public class KboatBuzzGCD
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.println("1. Buzz number");
        System.out.println("2. Calculate GCD");
        System.out.print("Enter your choice: ");
        int choice = in.nextInt();

        switch (choice) {
            case 1:
                System.out.print("Enter a number: ");
                int num = in.nextInt();
                if (num % 10 == 7 || num % 7 == 0)
                    System.out.println(num + " is a Buzz Number");
                else
                    System.out.println(num + " is not a Buzz Number");
            break;

            case 2:
                System.out.print("Enter first number: ");
                int a = in.nextInt();
                System.out.print("Enter second number: ");
                int b = in.nextInt();
                while (b != 0) {
                    int t = b;
                    b = a % b;
                    a = t;
                }
                System.out.println("GCD = " + a);
                break;

            default:
            System.out.println("Incorrect Choice");
            break;
        }
    }
}