--3Tunnel with Torches
function digIt()
while turtle.detect() do turtle.dig() os.sleep(0.5)
end
turtle.forward()
while turtle.detectDown() or turtle.detectUp() do turtle.digUp() turtle.digDown()
end
end

function placeTorch()
turtle.select(16)
turtle.placeUp()
end

local run = 0
term.write("Tunnel length: ")
run = read()

for i = 1, run do
k = i - 1
j = k % 4
digIt()
turtle.turnLeft()
digIt()
turtle.turnRight()
turtle.turnRight()
turtle.forward()
digIt()
turtle.back()
turtle.turnLeft()
if i == 2 or j == 1 then turtle.back() turtle.turnRight() turtle.forward() placeTorch() turtle.back() turtle.back() placeTorch() turtle.forward() turtle.turnLeft() turtle.forward()
end
end