using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

        // As TakeWhile iterates over the array: 

        //   "n" is the value of the element

        //   "index" is the index of the element

        var firstSmallNumbers = numbers.TakeWhile((n, index) => n >= index);

        foreach(var n in firstSmallNumbers)

            Console.WriteLine(n);

    }

}