Obsidian

shell.run("clear")
print("Length:")
l = io.read()
print("Width:")
b = io.read()
turtle.digDown()
turtle.down()
c = b / 2
b = c
d = l - 1
l = d

while b > 0 do
  while l >0 do
    turtle.dig()
    turtle.forward()
    l = l - 1
  end
  turtle.turnRight()
  turtle.dig()
  turtle.forward()
  turtle.turnRight()
  l = d
  while l > 0 do
    turtle.dig()
    turtle.forward()
    l = l - 1
  end
  turtle.turnLeft()
  turtle.dig()
  turtle.forward()
  turtle.turnLeft()
  b = b - 1
  l = d
end
turtle.turnLeft()
c = c * 2
while c > 0 do
  turtle.forward()
  c = c - 1
end
turtle.turnRight()
turtle.up()
turtle.backward()