m = peripheral.wrap("right")
ae = peripheral.wrap("left")
m.clear()
m.setCursorPos(1,1)

local function centerText(text)
  x,y = m.getSize()
  x1,y1 = m.getCursorPos()
  m.setCursorPos((math.floor(x/2) - (math.floor(#text/2))), y1)
  m.write(text)
end

--Call function "centerText("")" to set text
--Use m.setCursorPos(1,y) to choose placement on screen

y2 = 1


while true do
	m.clear()
	m.setCursorPos(1, y2)
	m.setTextColor(colors.yellow)
	centerText(ae.countOfItemType(4, 0))
end