Test

local x = 5
local y = 5
local z = 4

for i=1, z do
    if i>1 then
        while turtle.detectDown() do
            turtle.digDown()
            sleep(0.1)
        end
        turtle.down()
    end
    for j=1, y do
        if j>1 then
            turtle.turnRight()
            while turtle.detect() do
                turtle.dig()
                sleep(0.1)
            end
            turtle.forward()
            turtle.turnLeft()
        end
        for k=1, x do
            if turtle.getFuelLevel() ~= "unlimited" and turtle.getFuelLevel() < 1 then
                turtle.refuel(5)
            end
            if turtle.getItemCount(1)<8 or turtle.getItemCount(16)~=0 then
                turtle.refuel(turtle.getItemCount(1)-1)

                for l=1, k do
                    turtle.back()
                end

                turtle.turnLeft()
                for l=1, j do
                    turtle.forward()
                end
                turtle.turnRight()

                for l=1, i do
                    turtle.up()
                end

                turtle.turnLeft()
                for l=2, 16 do
                    turtle.select(l)
                    turtle.drop()
                end
                turtle.turnRight()

                turtle.select(1)
                turtle.suckUp(64-turtle.getItemCount(1))
                if turtle.getItemCount(1)<64 then
                    os.shutdown()
                end

                for l=1, i do
                    turtle.down()
                end

                turtle.turnRight()
                for l=1, k do
                    turtle.forward()
                end
                turtle.turnLeft()

                for l=1, j do
                    turtle.forward()
                end

            else
                while turtle.detect() do
                    turtle.dig()
                    sleep(0.1)
                end
                turtle.forward()

            end
        end
        for k=1, x do
            turtle.back()
        end
    end
    turtle.turnLeft()
    for k=1, y do
        turtle.forward()
    end
    turtle.turnRight()
end
for l=1, z do
    turtle.up()
end