Countdown Timer

local countdown = 120
local mon = peripheral.wrap("top")
mon.setTextScale(2)
while countdown > 0 do
  countdown = countdown - 1
  local minutes = math.floor(countdown / 60)
  local seconds = string.format("%02d", countdown % 60)
  mon.clear()
  mon.setCursorPos(1,1)
  mon.write(minutes..":"..seconds)
  os.sleep(1)
end