using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(IsNumeric("123"));

        Console.WriteLine(IsNumeric("1a3"));

        Console.WriteLine(IsNumeric("xx223.2"));

        Console.WriteLine(IsNumeric("22.0"));

    }

    public static bool IsNumeric(string value)

    {

        return value.All(char.IsNumber);

    }

}