CC Destruction

local R=0
print("Turtle starts at Top/Right/Back Corner!")
print("")
print("Starting position, UP/DOWN? 0:No , ..,-2,-1,1,2,..")
local strZ=read()+0
print("Starting position, Forward? 0:No , 1,2,..")
local strX=read()+0
print("Length/Forward? (min. 1)")
local Len=read()+0
print("Width? (min. 1)")
local Wid=read()+0
print("Height/Depth? (min. 1)")
local Dep=read()+0
print("chose: 1 = back to start position")
print("       0 = stay in End position")
local PZ=read()+0
local PX=0
local PY=0
if strZ>0 then
    for a=1, strZ do
        while turtle.detectUp() do
            turtle.digUp()
        end
    turtle.up()
    end
elseif strZ<0 then
    for a=-1, strZ,-1 do
        while turtle.detectDown() do
            turtle.digDown()
        end
        turtle.down()
    end
end
if strX>0 then
    for a=1,strX do
        while turtle.detect() do
            turtle.dig()
        end
        turtle.forward()
    end
end

for z=1,Dep do
    for y=1,Wid do
        for x=1,Len do
            if x<Len then
                while turtle.detect() do
                    turtle.dig()
                end
                turtle.forward()
                if turtle.getFuelLevel()<10 then
                    for a=1,16 do
                        turtle.select(a)
                        turtle.refuel()
                    end
                end
            else
                if PX==0 then
                    PX=1
                else
                    PX=0
                end
            end
        end
        if y<Wid then
            if R==0 then
                turtle.turnLeft()
                while turtle.detect() do
                    turtle.dig()
                end
                turtle.forward()
                turtle.turnLeft()
                R=1
            else
                turtle.turnRight()
                while turtle.detect() do
                    turtle.dig()
                end
                turtle.forward()
                turtle.turnRight()
                R=0
            end
        else
            if PY==0 then
                PY=1
            else
                PY=0
            end
        end
    end
    if z<Dep then
        if turtle.detectDown() then
            turtle.digDown()
        end
        turtle.down()
        turtle.turnLeft()
        turtle.turnLeft()
    end
end
if PZ==1 then
    for z=2,Dep do
        turtle.up()
    end
    if PX==1 then
        turtle.turnLeft()
        turtle.turnLeft()
        for x=2,Len do
            turtle.forward()
        end
    end
    if PY==1 then
        turtle.turnLeft()
        for y=2,Wid do
            turtle.forward()
        end
        turtle.turnRight()
    end
    for x=1,strX do
        turtle.forward()
    end
    if strZ>0 then
        for z=1,strZ do
            turtle.down()
        end
    elseif strZ<0 then
        for z=-1,strZ,-1 do
            turtle.up()
        end
    end
end