using static System.Console;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        var str = "Plano Liberty Empresa +50 - 043-98965-2784(058/PÓS/SMP)";

        Match match = Regex.Match(str, @"(\d{3}-\d{5}-\d{4})");

        Write(match.Groups[1].Value);

    }

}