exit = false

def encriptar(txt)
  text_arr = []
  puts "Introduce un texto:"
  txt.each_byte { |c| text_arr << (c.ord + 2).chr; }
  texto = text_arr.join
end

def desencriptar(txt)
  if txt == ''
    puts "Encripta primero..."
  else
    mostrar_arr = []
    txt.each_byte { |c| mostrar_arr << (c.ord - 2).chr }
    texto = mostrar_arr.join
  end
end

while !exit
  puts "1 - Encriptar || 2 - Desencriptar || 0 - Salir"
  case opt = gets.to_i
  when 1 then puts encriptado = encriptar(gets.chomp)
  when 2 then puts desencriptar(encriptado)
  when 0
    puts "Hasta luego!!!"
    exit = true
  else
    puts "OPCION INCORRECTA, ¡PRUEBA OTRA VEZ!"
  end
end