Alison has a large number of coloured pencils. When the pencils are divided between two of her friends there is one pencil left over. If they are divided between three friends there are two left over. Between four friends there would be three left over. Between five friends there would be four left over.  What is the smallest number of coloured pencils that Alison could have? 
Overseas Competition->Knowledge Point->Number Theory Modules->Remainder Problems