I'm trying to write conditionals for my program

I am running a program where I want the use to be able to select 1-28 and the program will print_details. However if the user types in ANYTHING else I want to print an error.

def list_menu
     puts "Type the episode number you want more information on.".cyan
    
     input = gets.strip
    #  if input.between? (0, 27)
# #ask for user input
# #validate user input with a conditional
    print_details(gets.strip)
    
#      elsif
#      puts "That's not a valid number!"
#      list_menu
    
  
     puts "Is there another episode you would like details on? Y/N".cyan

     input = gets.strip
     if input == "Y"
        list_episode
        list_menu
     elsif input == "y"
        list_episode
        list_menu
     elsif input == "N"
      bye
     elsif input == "n"
      bye
     else
      puts "ERROR".red
      list_menu
      
    end
  end

I have commented out what I was attempting. As of right now the program runs, but if I were to type "0" it would print details from the last episode