local x = 1
local y = 1

local monitor = peripheral.wrap("top")

while true do
    os.pullEvent("redstone")
    if rs.getInput("bottom") then
        -- start timer
        for i = 60,0,-1 do
            monitor.clear()
            monitor.setCursorPos(x, y)
            monitor.write(tostring(i))
            sleep(1)
        end
        -- end of timer
    end
end