using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var list = new List<int>(){1,5,7,3,19};

        var index = list.FindIndex(x=>x == 5);

        Console.WriteLine(index);

        Func<int, int> func1 = x => x + 1;

        Console.WriteLine(func1.Invoke(6));

        Func<int, int, int> multiply = (x,y) => x * y;

        Console.WriteLine(multiply.Invoke(4,5));

    }

}