using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        var list = new List<string>(){"MGR00001", "MGR00003", "MGR00004", "MGR00010", "MGR00044", "MGR00050", "MGR00070", "MGR00071", "MGR00072", "MGR00131"};

        var a = false;

        var t = "SER000";

        if(!t.StartsWith("SER") && (!t.StartsWith("MGR")  || list.Contains(t)))

        {

            a=true;

        }

        Console.WriteLine(a);

    }

}