function mineUp()
    if turtle.compareUp() then
        turtle.digUp();
    end
    sleep(0.1);
end

function mineDown()
    if turtle.compareDown() then
        turtle.digDown();
    end
    sleep(0.1);
end

function mineForward()
    if turtle.compare() then
        turtle.dig();
    end
    sleep(0.1);

    blocksMined = blocksMined + 1;
end

local blocksMined = 0;

turtle.select(2);

while true do
    if turtle.getFuelLevel() == 0 then
        turtle.select(1);
        turtle.refuel();
        turtle.select(2);
    end

    mineForward();
    mineUp();
    mineDown();
    turtle.turnLeft();
    mineForward();
    turtle.turnRight();
    turtle.turnRight();
    mineForward()
    turtle.turnLeft();
    sleep(1);
    local fwd = turtle.forward();
    if not fwd then
        break;
    end
    sleep(1);

    if blocksMined == 30 then
        turtle.turnLeft();
        sleep(0.1)
        turtle.turnLeft();
        turtle.select(1);
        turtle.refuel();
        turtle.select(2);
    elseif blocksMined == 60 then
        break;
    end

    sleep(0.1);
end