using System.Collections.Generic;
public static void Main()
Dictionary<int, List<string>> LEVEL_SOLUTIONS = new Dictionary<int, List<string>>()
{1, new List<string>(){"level2","level 2"} }
var apantisi1 = "level 2";
var apantisi2 = "LEVEL2";
Console.WriteLine(LEVEL_SOLUTIONS[1].Contains(apantisi1.ToLower().Trim()));
Console.WriteLine(LEVEL_SOLUTIONS[1].Contains(apantisi2.ToLower().Trim()));