write ("Greetings!")
write ("Set length: ")
l=read()
write ("Set number of 3x1 tunnels: ")
Nturns=read()
write ("Set number of height (0 if 1 level): ")
Nheight=read()
write ("Set where you want to dig (up=1, down=0): ")
drn=read()
write ("Set which side you want to dig (left=1, right=2): ")
side=read()

function Pullback(l,lCur,Face,NtCur,NhCur,side)
  if NhCur>0 then
    for i=1,NhCur do turtle.down() end
  end
  if Side==1 then
    if Face==1 then
      turtle.turnleft()
    else turtle.turnright()
    end
  else
    if Face==1 then
      turtle.turnright()
    else turtle.turnleft()
    end
  end
  if NtCur>0 then
    for i=1,NtCur do turtle.forward() end
  end
  if Side == 1 then turtle.turnright() else turtle.turnleft() end
  if Face == 1 then
    for i=1,(l-lCur) do turtle.forward() end
  else for i=1,lCur do tutle.forward() end
  end
  for i=2,16 do
    turtle.select(i)
    turtle.drop(i)
  end
  turtle.select(1)
  turtle.turnright()
  turtle.turnright()

  if Face==1 then for i=1,(l-lCur) do turtle.forward() end
  else for i=1,lCur do turtle.forward() end
  end
  if NtCur>0 then
    if Side==1 then turtle.turnleft() else turtle.turnright() end
    for i=1,NtCur do turtle.forward() end
    if Side==1 then
      if Face==1 then turtle.turnleft() else turtleturnright() end
    else
      if Face==1 then turtle.turnright() else turtle.turnleft() end
    end
  end
  if NhCur >0 then
    for i=1,NhCur do turtle.up() end
  end
end

function FC()
  Flag=true
  while Flag==true do
    Fuel=turtle.getFuelLimit()
    if Fuel<500 then
      turtle.refuel(10)
      else Flag=false
    end
  end
end

function SC()
  Nfull=0
  for s=2,9 do
    count=turtle.getItemCount(s)
    if count==64 then
      Nfull=Nfull+1
    end
  end
  if Nfull==15 then
    Pullback(l,lCur,Face,NtCur,NhCur)
  end
end

function Turning(side)
  if side==1 then
    turtle.turnLeft()
  else
    turtle.turnRight()
  end
  turtle.dig()
  while turtle.detect()==true do
    turtle.dig()
  end
  turtle.forward()
  turtle.digUp()
  while turtle.detect()==true do
    turtle.digUp()
  end
  turtle.digDown()
  if Side==1 then
    turtle.turnLeft()
  else
    turtle.turnRight()
  end
end

function Forw()
  turtle.dig()
  turtle.digUp()
  turtle.digDown()
  while turtle.detectUp()==true do
    turtle.digUp()
  end
  while turtle.detect()==true do
    turtle.dig()
  end
  turtle.forward()
end

function Height(Drn)
  turtle.turnLeft()
  turtle.turnLeft()
  if drn==1 then
    for i=1,3 do
      turtle.up()
      turtle.digUp()
      while turtle.detectUp()==true do
        turtle.digUp()
      end
    end
  else
    for i=1,3 do
      turtle.down()
      turtle.digdown()
    end
  end
end



FC()
lCur=1
NtCur=0
NhCur=0
Face=0
for i=1,Nheight do
  for j=0,Nturns do
    Face=bit.band(j,1)
    for k=1,l do
      lCur=k
      Forw()
      FC()
      SC()
    end
    Turning(Side)
    NtCur=NtCur+1
    FC()
    SC()
  end
  if Side==1 then turtle.turnleft() else turtle.turnright() end
  for i=1,Nturns do turtle.forward() end
  if Side==1 then turtle.turnlefr() else turtle.turnright() end
  Height(Drn)
end