Rio de Janeiro is a very beautiful city, but there are so many places to visit that sometimes you feel overwhelmed, Fortunately, your friend Bruno has promised to be your tour guide.
Unfortunately, Bruno is terrible driver. He has a lot of traffic fines to pay and is eager to avoid paying more. Therefore he wants to know where all the police cameras are located so he can drive more carefully when passing by them. These cameras are strategically distributed over the city, in locations that a driver must pass through in order to travel from one zone of the city to another. A location C will have a camera if and only if there are two city locations A and B such that all paths from A to B pass through a location C.
For instance, suppose that we have six locations (A, B, C, D, E, and F) with seven bidirectional routes B – C, A – B, C – A, D – C, D – E, E – F, and F – C. There must be a camera on C because to go from A to E you must pass through C. In this configuration, C is the only camera location.
Given a map of the city, help Bruno avoid further fines during your tour by writing a program to identify where all the cameras are.
The input will consist of an arbitrary number of city maps, where each map begins with an integer N ( 2 < N<=100) denoting the total number of locations in the city. Then follow N different place names at one per line, where each place name will consist of least one and at most 30 lowercase letters. A non-negative integer R then follows, denoting the total routes of the city. The next R lines each describe a bidirectional route represented by the two places that the route connects.
Location names in route descriptions will always be valid, and there will be no route from one place to itself. You must read until N = 0, which should not be processed.
For each city map you must print the following line:
City map #d: c camera(s) found
where d stands for the city map number (starting from 1) and c stands for the total number of cameras. Then should follow c lines with the location names of each camera in alphabetical order. Print a blank line between output sets.
6 sugarloaf maracana copacabana ipanema corcovado lapa 7 ipanema copacabana copacabana sugarloaf ipanema sugarloaf maracana lapa sugarloaf maracana corcovado sugarloaf lapa corcovado 5 guanabarabay downtown botanicgarden colombo sambodromo 4 guanabarabay sambodromo downtown sambodromo sambodromo botanicgarden colombo sambodromo 0
City map #1: 1 camera(s) found sugarloaf City map #2: 1 camera(s) found sambodromo