local h = 1
local fuelSlot = 1
local stonePlace = 5
local stoneReserve = 6
local glassPlace = 9
local glassReserve = 10

local blanks = 0

function filler()
 if turtle.getFuelLevel()<10 then
  turtle.select(fuelSlot)
  turtle.refuel(1)
 end
 if turtle.getItemCount(stonePlace)<3 then
  turtle.select(stoneReserve)
  turtle.transferTo(stonePlace)
 end
 if turtle.getItemCount(glassPlace)<3 then
  turtle.select(glassReserve)
  turtle.transferTo(glassPlace)
 end

 turtle.select(stonePlace)
end

function digMove()
 turtle.down()
 turtle.digDown()
end

function digToBedrock()
 turtle.digDown()
 while not turtle.detectDown() do
  filler()
  digMove()
 end
end

function checkForward()
  turtle.select(glassPlace)
  if (not turtle.detect()) or (turtle.compare()) then
    blanks = blanks + 1
  end
end

function placeWhat()
  blanks = 0
  checkForward()
  turtle.turnLeft()
  checkForward()
  turtle.turnRight()
  turtle.turnRight()
  checkForward()
  turtle.turnLeft()
  if (blanks == 0) then
   turtle.select(stonePlace)
  else
    turtle.select(glassPlace)
  end
end

function movePlace()
 if turtle.up() then
  turtle.placeDown()
  h = h + 1
 else
  turtle.digUp()
 end
end

digToBedrock()

while h < 120 do
 filler()
 if h < 70 then
   placeWhat()
 else
   turtle.select(stonePlace)
 end
 movePlace()
end

run()