Tree Chopper

local length = 6
local width = 6
local height = 6

function ChopTreeLine()
        for i=1,length,1 do
            turtle.dig()
        turtle.forward()
        turtle.digUp()
        end
    turtle.turnRight()
    turtle.dig()
        turtle.forward()
    turtle.turnRight()
        turtle.digUp()
    for i=1,length,1 do
            turtle.dig()
        turtle.forward()
        turtle.digUp()
        end
        turtle.turnLeft()
    turtle.dig()
        turtle.forward()
    turtle.turnLeft()
        turtle.digUp()
end

function ClearBlock()
    for j=1,(width/2),1 do
        ChopTreeLine()
    end
end

function MoveToNextLayer()
    turtle.turnLeft()
    for k=1,width,1 do
        turtle.forward()
    end
    turtle.turnRight()
    turtle.digUp()
    turtle.up()
    turtle.digUp()
    turtle.up()
end

function Chop()
    for l=1,(height/2),1 do
        ClearBlock()
        MoveToNextLayer()
    end
    for l=1,height,1 do
        turtle.down()
    end
    for i=1,16,1 do
                turtle.select(i)
                turtle.drop(turtle.getItemCount(i))
        end
        turtle.select(1)
end

print("Please input Chop Length - MUST BE MULTIPLE OF 2")
length = tonumber(read())
print("Please input Chop Width - MUST BE MULTIPLE OF 2")
width= tonumber(read())
print("Please input Chop Height - MUST BE MULTIPLE OF 2")
height= tonumber(read())

print("Current Fuel Level:")
print(turtle.getFuelLevel())
print("Would you like to refuel (y/n)?")
input = io.read()
if input == "y" then
        print("Refueling all of Slot 1 in 5s")
        sleep(5)
        turtle.select(1)
        turtle.refuel(turtle.getItemCount(1))
else
        print("Did not refuel.")
end
print("Beginning Chop!")
Chop()