using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        List<string> strings = new List<string>() { "A", "B", "C" };

        Console.WriteLine("Before:");

        foreach(string s in strings)

        {

            Console.WriteLine(s);

        }

        strings.RemoveAll(x => x == "B");

        Console.WriteLine("After:");

        foreach(string s in strings)

        {

            Console.WriteLine(s);

        }               

    }

}