Stripmining

i=8
j=21
k=0
a=0
right=true

function fforward()
    while(not turtle.forward()) do
        turtle.dig()
    end
    a=a+1
    while(turtle.detectUp()) do
        turtle.digUp()
        sleep(0.4)
    end
    if not turtle.detectDown() then
        turtle.select(1)
        turtle.placeDown()
    end
    if(a==12) then
        a=0
        placeTorch()
    end
end



function placeTorch()
    turtle.turnRight()
    turtle.turnRight()
    turtle.select(2)
    turtle.place()
    turtle.turnRight()
    turtle.turnRight()
end

function Up()
    for e=1,4 do
        while(not turtle.Up) do
            turtle.digUp()
        end
    end

end

write("cobblestone in slot 1\n")
write("fakeln in slot 2\n")
write("anzahl der stockwerke:")
k=tonumber(read())

while(true) do
    for h=1,k do
        for f=1,i do
            for g=1,j do
                fforward()
            end
            if(f<8) then
                if right then
                    turtle.turnRight()
                else
                    turtle.turnLeft()
                end
                fforward()
                fforward()
                fforward()
                if right then
                    turtle.turnRight()
                    right=false
                else
                    turtle.turnLeft()
                    right=true
                end
            else
                fforward()
                Up()
                turtle.turnRight()
                turtle.turnRight()
            end
        end
    end
end