Hole

print("Length:")
local length = read()
print("Depth:")
local depth = read()

function Turn()
  for i = 1,2 do
    turtle.turnLeft()
  end
end

function TurnHalf()
  turtle.turnRight()
end

function ChangeY()
  Turn()
  turtle.digDown()
  turtle.down()
end

function ChangeYHalf()
  TurnHalf()
  turtle.digDown()
  turtle.down()
end

function Branch()
  for i = 1,(length-1) do
    turtle.dig()
    turtle.forward()
  end
end

function BranchToLeft()
  turtle.turnLeft()
  turtle.dig()
  turtle.forward()
  turtle.turnLeft()
  Branch()
end

function BranchToRight()
  turtle.turnRight()
  turtle.dig()
  turtle.forward()
  turtle.turnRight()
  Branch()
end

function Layer()
  if math.fmod(length, 2) ~= 0 then
    Branch()
    for i = 1,((length-1)/2) do
      BranchToRight()
      BranchToLeft()
    end
  else
    Branch()
    for i = 1,((length-2)/2) do
      BranchToRight()
      BranchToLeft()
    end
    BranchToRight()
  end
end

for i = 1,(depth-1) do
  Layer()
  if math.fmod(length, 2) ~= 0 then
    ChangeY()

  else
    ChangeYHalf()
  end
end
Layer()