using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

   string[] words = { "aPPLE", "BlUeBeRrY", "cHeRry" }; 

        var s=words.Select(x=>x.ToUpper());

        foreach(var word in s)

        {

            Console.WriteLine(word);

        }

}

    }

​