I think so - I started doing a binary search >50000 -> <75000 -> <65000 -> <55000 -> <52500 then wondered if it was 50000, so guessed that. It said I was right,

I think so - I started doing a binary search >50000 -> <75000 -> <65000 -> <55000 -> <52500 then wondered if it was 50000, so guessed that. It said I was right, well done, the answer is indeed 02563!