import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner keyboard = new Scanner (System.in);

        System.out.println("Square Root!");
        System.out.println("Enter a Number: ");
        int entry = keyboard.nextInt();

        if (entry < 0)
        do {
            System.out.println("You can't take the square root of a negative number, Silly.");
            System.out.println("Try again: ");
            entry = keyboard.nextInt();

        } while (entry < 0);
        double num = Math.sqrt(entry);
        System.out.println("The square root of " + entry + " is " + num);
    }
}