local monitor = peripheral.wrap("top")

local n = 0
while true do
    local w, h = monitor.getSize()
    monitor.clear()
    monitor.setCursorPos(1, h)
    monitor.blit("-", "0", "e")
    monitor.setCursorPos(w, h)
    monitor.blit("+", "0", "d")

    monitor.setCursorPos(1, 1)
    monitor.write("COUNTER")

    monitor.setCursorPos(1, 2)
    monitor.write(("%.0f"):format(n))

    local event, side, xPos, yPos = os.pullEvent("monitor_touch")
    if xPos == 1 and yPos == h then
        n = n - 1
    elseif xPos == w and yPos == h then
        n = n + 1
    end
end