import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        System.out.println("Square Root Calculator. Please Input a Number:");
        int n = keyboard.nextInt();
        do {
            if (n<0){
                System.out.println("That number is negative, please input a positive number.");
                System.out.println("Input a Number:");
                n = keyboard.nextInt();
            }
        } while (n < 0);{
            double sqrt = Math.sqrt(n);
            System.out.println("The square root of " +n+ " is " +sqrt);
        }
        }

    }