Let's consider the previous problem, where a farmer had a successful year and harvested 5580 kg of potatoes, with 588 kg being of low quality and couldn't be sold. 

But what if the original harvest was not as bountiful as we first thought, and the farmer only harvested 5080 kg instead of 5580 kg. In this case, keeping the same 588 kg of low quality that couldn't be sold, how many kg of good quality potatoes would the farmer have?