using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var input = new List<string>() { "a", "b", "c" };

        input.Contains("A", StringComparer.InvariantCultureIgnoreCase).Dump();

        input.Any(x => string.Equals(x, "A", StringComparison.InvariantCultureIgnoreCase)).Dump();

    }

}