Bebras 2019 - Level 3 Question 13

Six cats are going to the mice’s party by jumping across islands in the river. They may jump only to adjacent islands. They cannot jump diagonally or jump onto or across submerged islands. Each cat stays on an island for exactly 1 minute before jumping to another empty island. Jumping time is negligible. If there is no empty neighbouring island, the cat must stay for another minute.



What is the minimum number of minutes needed for all six cats to reach the mice’s party?