using System;
using System.Globalization;
using System.Linq;
using System.Collections.Generic;

public class Test
{
    
    public static string RemoveFirstLine(string input)
    {
        var lines = input.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
        return string.Join(Environment.NewLine, lines.Skip(1).ToArray()); //ideone uses .NET 3.5
    }
    
	public static void Main()
	{ 
            string str = @"-- REMOVE ME --
                        Line 2
                        Line 3
                        Line 4
                        Line 5";
            str = RemoveFirstLine(str);
          Console.Write(str);
	}
}