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Recently, Melody built a little boat, as cute as it could be. And she put a |
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number of animals, two-by-two, on her little boat on the sea! |
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Melody's boat features **N** rooms, numbered from 1 to **N**. The contents of |
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the _i_th room are described by the string **Ai**. If **Ai** = "-", then the |
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room is empty, while otherwise the room contains an animal of species **Ai** |
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(where **Ai** is a case-sensitive alphanumeric string made up of lowercase |
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letters "a"..."z", uppercase letters "A"..."Z", and digits "0"..."9"). There |
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are **at most two animals of any given species** on the boat. |
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There are **N**-1 corridors in the boat, the _i_th of which allows Melody and |
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the animals to travel in either direction between rooms **Xi** and **Yi**. |
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Each room is reachable from each other room by following a sequence of |
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corridors. |
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It's time for Melody's daily walk through her boat! She'd like to choose one |
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room to start in and a different room to end in, and walk from the former to |
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the latter. She'll take the unique path which allows her to do so without |
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visiting any room multiple times. Along the way, any time she finds herself in |
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a room containing an animal (including the starting or ending room), that |
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animal will join her for the remainder of her walk. Normally, both Melody and |
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the animals will keep quiet, which is just how she likes it. However, if two |
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animals of any given species ever end up joining her, they'll promptly make a |
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racket talking to one another, which is no good! As such, she'll refuse to |
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take a walk which would result in encountering two of any species of animal. |
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For how many of the **N***(**N**-1) possible ordered pairs of starting/ending |
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rooms would it be possible for Melody to enjoy a quiet walk from one to the |
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other? |
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### Input |
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Input begins with an integer **T**, the number of boats. |
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For each boat, there is first a line containing the integer **N**. |
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Then, **N** lines follow, the _i_th of which contains the string **Ai**. |
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Then, **N** \- 1 lines follow, the _i_th of which contains the space-separated |
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integers **Xi** and **Yi**. |
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### Output |
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For the _i_th boat, print a line containing "Case #_i_: " followed by one |
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integer, the number of valid ordered pairs of starting and ending rooms for |
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Melody's walk. |
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### Constraints |
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1 ≤ **T** ≤ 95 |
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2 ≤ **N** ≤ 800,000 |
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1 ≤ **Xi**, **Yi** ≤ **N** |
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1 ≤ |**Ai**| ≤ 10 |
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The sum of **N** across all **T** test cases is no greater than 4,000,000. |
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### Explanation of Sample |
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In the first case, the 4 starting/ending room pairs (1, 2), (2, 1), (2, 3), |
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and (3, 2) are valid. On the other hand, the pairs (1, 3) and (3, 1) are not. |
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For example, on the way from room 1 to room 3, a Fox would begin following |
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Melody around in room 1, and upon being joined by another Fox in room 3, the |
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two Foxen would begin making strange noises towards one another. |
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In the second case, both possible starting/ending room pairs ((1, 2) and (2, |
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1)) are no good, as they would involve encountering two talkative Turtles. |
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In the third case, both possible starting/ending room pairs will do, as no two |
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animals of any given species can be encountered. |
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