为了给奶牛贝茜庆生，约翰允许她在自己最肥沃的土地里自由的吃草。
该片土地中共有 N 块草地，编号 1∼N。
每块草地的青草质量都不相同。
如果贝茜吃了质量为 Q 的草，则会获得 Q 单位的能量。
每块草地都通过双向道路最多与十块其他草地连接。
贝茜沿一条道路从一块草地走到另一块草地需要花费能量 E。
贝茜可以选择在任意一块草地开吃，在积累了最大的能量后，她将停止。
不幸的是，贝茜是一个挑剔的牛。
一旦她吃了一定质量的草，她就再也不会吃质量等于或低于该质量的草了！
当她经过一片草地时，她可以选择不吃该草地的草。
事实上，她发现略过一些高质量的草，稍后折返享用十分有益。
请帮助贝茜计算她能积累的最大能量。
第一行包含 N 和 E。
接下来 N 行，每行描述一块草地。首先包含两个整数 Q 和 D，分别表示草地质量以及与其相连的草地数量，然后包含 D 整数，表示与其相连的草地编号。
输出贝茜可以积累的最大能量。
1≤N≤1000,
1≤E,Q≤106,
1≤D≤10
5 2 4 1 2 1 3 1 3 4 6 2 2 5 5 2 2 5 2 2 3 4
7
贝茜从第四块草地开始，从那里吃草获得 5 单位能量。
沿道路走到草地 5，损失 2 单位能量。
贝茜拒绝吃草地 5 的劣质草，直接消耗 2 单位能量前往草地 3。
在草地 3 吃草后，获得 6 单位能量。
此时，共积累 7 单位能量，这是能积累的最大能量。
For Bessie the cow’s birthday, Farmer John has given her free reign over one of his best fields to eat grass.
The field is covered in N patches of grass (1≤N≤1000), conveniently numbered 1…N, that each have a distinct quality value. If Bessie eats grass of quality Q, she gains Q units of energy. Each patch is connected to up to 10 neighboring patches via bi-directional paths, and it takes Bessie E units of energy to move between adjacent patches (1≤E≤1,000,000). Bessie can choose to start grazing in any patch she wishes, and she wants to stop grazing once she has accumulated a maximum amount of energy.
Unfortunately, Bessie is a picky bovine, and once she eats grass of a certain quality, she’ll never eat grass at or below that quality level again! She is still happy to walk through patches without eating their grass; in fact, she might find it beneficial to walk through a patch of high-quality grass without eating it, only to return later for a tasty snack.
Please help determine the maximum amount of energy Bessie can accumulate.
5 2 4 1 2 1 3 1 3 4 6 2 2 5 5 2 2 5 2 2 3 4
7
Bessie starts at patch 4 gaining 5 units of energy from the grass there. She then takes the path to patch 5 losing 2 units of energy during her travel. She refuses to eat the lower quality grass at patch 5 and travels to patch 3 again losing 2 units of energy. Finally she eats the grass at patch 3 gaining 6 units of energy for a total of 7 energy.
Note tha the sample case above is different from test case 1 when you submit.
[Problem credits: Austin Anderson and Brian Dean, 2015]