mine

term.write("Enter height: ")
h = read()
term.write("Enter width: ")
w = read()
term.write("Enter length: ")
l = read()
for y = 1,h,1 do
  for z = 1,w,1 do
    alt = -1+z
    for x = 1,l,1 do
      if(turtle.detect())
      then
        turtle.dig()
      end
      if(z > 1 and x < l)
      then
        turtle.forward()
      end
    end
    if(alt % 2 == 0)
    then
      turtle.turnLeft()
      turtle.dig()
      turtle.forward()
      turtle.turnLeft()
    else
      turtle.turnRight()
      turtle.dig()
      turtle.forward()
      turtle.turnRight()
    end
  end
  if(turtle.detectDown())
  then
    turtle.digDown()
  end
  turtle.down()
end