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A group of **N** Foxen reside in a peaceful forest community. Each Fox's |
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property consists of a tree stump as well as an underground den. There are |
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**N** \- 1 two-way paths on the ground running amongst the tree stumps, with |
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the _i_th path connecting the stumps belonging to two different Foxen **Ai** |
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and **Bi**, such that all **N** stumps can be reached from one another by |
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following a sequence of paths. Similarly, there are **N** \- 1 underground |
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tunnels running amongst the dens, with the _i_th tunnel connecting the dens |
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belonging to Foxen **Ci** and **Di**, such that all **N** dens can be reached |
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from one another. There's additionally a passageway connecting the tree stump |
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and den belonging to the 1st Fox, which is the only way in the whole forest to |
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get underground from the surface and vice versa. |
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At night the Foxen sleep in their dens, but during the daytime, they like to |
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emerge and relax lazily on their tree stumps. Each day, every Fox takes a trip |
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from their den to their tree stump, taking the unique shortest path through |
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the system of tunnels and paths to get there. However, this often requires |
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passing through other Foxen's properties, which they don't appreciate a whole |
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lot. To compensate, the Foxen have started charging each other tolls for said |
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passage. They don't have much of a currency, but Foxen do love crackers, so |
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those will do. Over a given period of **M** days, on the _i_th day, two |
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different Foxen **Wi** and **Xi** will each charge tolls for one of their |
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pieces of property. If **Yi** = "T", then Fox **Wi** will be charging tolls |
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for passage through their tree stump. Otherwise, if **Yi** = "D", then Fox |
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**Wi** will instead be charging tolls for passage through their den. |
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Similarly, Fox **Xi** will be charging tolls for passage through either their |
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tree stump (if **Zi**= "T") or their den (if **Zi**= "D"). |
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Each day, whenever a Fox passes through another Fox's den or stump which is |
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subject to tolls on that day, they'll normally need to pay up with 2 crackers. |
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However, if they've already paid a toll earlier on that same trip, then the |
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property-owning Fox will take pity and only charge them 1 cracker instead of |
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2. As such, a Fox's daily trip may end up costing them at most 3 crackers. A |
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Fox will never charge themselves a toll, of course. If a pair of Foxen both |
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owe each other crackers, they'll still both pay up as normal, rather than |
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attempting to minimize the number of cracker transactions performed. |
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The Foxen are having some trouble keeping track of how many crackers they owe |
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one another. On each of the **M** days, they'd like to count up the total |
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number of crackers which will be charged as part of the tolls for the **N** |
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trips taken on that day. To avoid dealing with too many large numbers, they'd |
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like to combine these **M** cracker counts into a single value as follows |
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(where **Vi** is the _i_th day's count): |
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( ... (((**V1** * 12,345) + **V2**) * 12,345 + **V3**) ... * 12,345 + **VM**) |
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modulo 1,000,000,007 |
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Please help the Foxen compute this combined value! |
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### Input |
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Input begins with an integer **T**, the number of different communities of |
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Foxen. For each community of Foxen, there is first a line containing the |
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space-separated integers **N** and **M**. Then **N - 1** lines follow, the |
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_i_th of which contains the space-separated integers **Ai** and **Bi**. Then |
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**N - 1** lines follow, the _i_th of which contains the space-separated |
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integers **Ci** and **Di**. Then **M** lines follow, the _i_th of which |
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contains the integers **Wi** and **Xi** and the characters **Yi** and **Zi**, |
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all separated by spaces. |
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### Output |
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For the _i_th community of Foxen, print a line containing "Case #**i**: " |
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followed by a single integer, the requested combined value based on the **M** |
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days' cracker counts, modulo 1,000,000,007. |
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### Constraints |
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1 ≤ **T** ≤ 30 |
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2 ≤ **N** ≤ 500,000 |
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1 ≤ **M** ≤ 500,000 |
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1 ≤ **Ai**, **Bi**, **Ci**, **Di**, **Wi**, **Xi** ≤ **N** |
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Both the sum of **N** values and the sum of **M** values across all **T** |
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cases do not exceed 1,500,000. |
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### Explanation of Sample |
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In the first case, Fox 1 doesn't need to pay any tolls to get from its den to |
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its tree stump, while Fox 2 must pay 2 crackers to complete its trip due to |
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passing through Fox's 1 tree stump. |
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In the second case, 5 crackers will be charged on the first day (the 3 Foxen |
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must pay 0, 2, and 3 crackers, respectively), 2 crackers will be charged on |
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the second day, and none will be charged on the third day. This results in a |
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final answer of (((5 * 12,345) + 2) * 12,345) + 0) modulo 1,000,000,007 = |
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762,019,815. |
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In the third case, 7, 6, and 4 crackers will be charged on each of the three |
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days, respectively. |
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