package com.company;
import java.io.IOException;
import java.util.Scanner;

public class Main {

    private static Scanner in = new Scanner(System.in);

    public static void main(String[] args) {

        double x = nextSafeDouble();

    }

    private static double nextSafeDouble()
    {
        double temp = 0;

        do
        {
            try
            {
                temp = in.nextDouble();
                break;
            }
            catch (Exception e)
            {
                System.out.println ("Неверные данные");
            }
        } while(true);

        return temp;

    }

    /*private static double calculate(double x, double y)
    {
         return (Math.abs(Math.sin(x) - y) + 2 * x) / (Math.sqrt(1 + Math.abs(x * y)));
    }*/
}