Nowadays, mail delivery through postal order has been increased a lot in Chatgao city and there is only one postman in the city. Every day he has to run through almost all the roads in the city. As he is very much lazy, he is tired of this and wants to make a plan to get rid of it. According to his new plan, he will always start his mail delivery from a house and go through some distinct houses, will come back to the starting house and take rest, then he will go through another route of distinct houses and will come back to the starting house again. Note that the houses of the first and second round should also be different. He calls these types of routes dumbbell routes. Now he is curious about how many dumbbell routes are there in the city. As he is a lazy person he gives the job to find the number of dumbbell routes in the city Chatgao to you. Formally, there are N houses C0, C1, ..., CN−1. Available road connections between houses are also provided as input. A dumbbell route is a sequence of houses Ck1 , Ck2 , ..., Ckp , ..., Ckq where
2/2 Sample Input 2 56 01 12 20 23 34 42 67 01 12 20 23 34 45 53 Sample Output Case 1: 1 Case 2: 0