Added multiple solution disambiguation to donuts question

Author: TianLangHin

competition/donuts/prob.md

@@ -24,7 +24,8 @@ Homer's stomach has unlimited capacity, but he begins his journey at one of the
 
 Your task is to pinpoint the **starting Krispy Kreme's index** that allows Homer to complete the entire circular route once, going clockwise, without collapsing. If it's impossible for him to make the full trip, return **-1**.
 
-Rest assured, there's at most one valid starting point.
+If there are more than one valid starting points, return the smallest one.
+Since Homer is lazy, ideally he doesn't want to start from a Krispy Kreme too far from his home (which is nearest to the first one).
 
 ## Input