goLeft = false
coalSlots = {1,5,9,13}
iFuel = 1
brickSlots = {2,3,4,6,7,8,10,11,12,14,15,16}
iBrick = 1
print("Enter L or R")
direction = read()
if direction == "l" then
    goLeft = true
end
print("Enter x:")
x = tonumber(read())
print("Enter y:")
y = tonumber(read()) - 1
yT = y

function refuelT ()
    turtle.select(coalSlots[iFuel])
    turtle.refuel()
    iFuel = iFuel + 1
end

function selectBrick ()
   turtle.select(brickSlots[iBrick])
   if iBrick < 12 then
       iBrick = iBrick + 1
   else
       iBrick = 1
   end
end

refuelT()
selectBrick()
while x >= 1 do
    y = yT
    while y >= 1 do
        print("x: " .. x .. ", y: ".. y)
        turtle.digDown()
        if turtle.getItemCount() == 1 then
            selectBrick()
        end
        turtle.placeDown()
        turtle.digUp()
        turtle.dig()
        while turtle.detect() == true do
            turtle.dig()
            sleep(0.5)
        end
        turtle.forward()
        y = y - 1
    end
    print(x)
    if goLeft == true then
        turtle.digUp()
        turtle.digDown()
        if turtle.getItemCount() == 1 then
            selectBrick()
        end
        turtle.placeDown()
        turtle.turnLeft()
        turtle.dig()
        while turtle.detect() == true do
            turtle.dig()
            sleep(0.5)
        end
        turtle.forward()
        turtle.digUp()
        turtle.turnLeft()
        goLeft = false
    else
        turtle.digUp()
        turtle.digDown()
        if turtle.getItemCount() == 1 then
            selectBrick()
        end
        turtle.placeDown()
        turtle.turnRight()
        turtle.dig()
        while turtle.detect() == true do
            turtle.dig()
            sleep(0.5)
        end
        turtle.forward()
        turtle.digUp()
        turtle.turnRight()
        goLeft = true
    end
    x = x - 1
end