CF819E Mister B and Flight to the Moon

In order to fly to the Moon Mister B just needs to solve the following problem. There is a complete indirected graph with $ n $ vertices. You need to cover it with several simple cycles of length $ 3 $ and $ 4 $ so that each edge is in exactly $ 2 $ cycles. We are sure that Mister B will solve the problem soon and will fly to the Moon. Will you?

The only line contains single integer $ n $ ( $ 3

If there is no answer, print -1. Otherwise, in the first line print $ k $ ( $ 1