import java.util.Scanner;

class Oct17 {


	public static void main(String ... args) {

		Scanner kb = new Scanner(System.in);

		String option = null;

		do {

			printMenu();

			option = kb.next();
			
			switch(option) {
				case "1":
					optionOne();
					break;
				case "2":
					optionTwo();
					break;
				case "3":
					optionThree();
					break;
				case "exit":
					break;
				default:
					System.out.println("Invalid option");
				
			}

		} while(!option.equals("exit"));




	}
	
	static void printMenu() {
		System.out.println("1: option one");
		System.out.println("2: option two");
		System.out.println("3: option three");
		System.out.println("exit: to exit ");
		System.out.print("Enter choice: ");
	}

	static void optionOne() {
		System.out.println("Doing option one ...");
	}

	static void optionTwo() {
		System.out.println("Doing option two ...");
	}

	static void optionThree() {
		System.out.println("Doing option three ...");
	}

}