using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        List<string> myList = new List<string>

        {

            "apple",

            "banana",

            "cherry",

            "apple"

        };

​

        string elementToFind = "banana";

​

        // Find the index of the element

        int index = myList.FindIndex(a => a == elementToFind);

​

        if (index != -1)

        {

            Console.WriteLine("The index of '" + elementToFind + "' in the list is " + index);

        }

        else

        {

            Console.WriteLine("The element '" + elementToFind + "' was not found in the list.");

        }

    }

}

​