turtle.select(1)
turtle.refuel()

dir = 1
for i = 1, 50 do
    currentrow = i
    currentdepth = 0
    while true do
        if turtle.detectDown() then
            turtle.digDown()
        end
        if turtle.detect() then
            while currentdepth > 0 do
                turtle.back()
                currentdepth = currentdepth - 1
            end
            break
        else
            turtle.forward()
            currentdepth = currentdepth + 1
        end
    end
    turtle.turnRight()
    turtle.forward()
    turtle.turnLeft()
    if turtle.getFuelLevel() < 10 then
        turtle.refuel()
    end
end