Statement

Giorgio has been trying very hard to enter in the exclusive Notary Club during the last few years. Finally, the club administration decided to consider his application, and set a date for his admission test. Following a long-standing tradition of the Notary Club, the would-be novice now has to book (and pay for) a dinner for the whole admission committee (consisting of K grandmasters). This is quite a problem for Giorgio, due to his very limited budget. In fact, the only place he is able to afford is "Wu Fung's -- Typical Chinese Pizza Kebab", an informal take-away place which also offers N comfortable stools, the i-th of them located X_i centimeters from the start of the counter. Giorgio knows very well Wu Fung's, and is worried that the rowdy customers of the place might jeopardize his chances of success. There is only one slight chance left: to carefully book K places (not necessarily consecutive) so as to maximise the distance between the grandmasters and the rowdy customers...