using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        var match = Regex.Match("240448.00", @"(?<number>-?\d+)");

        Console.WriteLine(match.Groups["number"]);

        match = Regex.Match("-240448.00", @"(?<number>-?-\d+)");

        Console.WriteLine(match.Groups["number"]);

    }

}