local nCount = 5
local nSleep = 1
local nWait = 5

while true do

	if rs.getInput("left") == true then
		for n=1,nCount do
			rs.setBundledOutput("back",1)
			sleep(nSleep)
			rs.setBundledOutput("back",0)
			sleep(nSleep)
		end

		sleep(nWait)

		for n=1,nCount do
			rs.setBundledOutput("back",2)
			sleep(nSleep)
			rs.setBundledOutput("back",0)
			sleep(nSleep)
		end
	end
end