1656: [Usaco2006 Jan] The Grove 树木 Time Limit: 5 Sec Memory Limit: 64 MB Submit: 143 Solved: 88 [Submit][Status][Discuss] Description The pasture contains a small, contiguous grove of trees that has no 'holes' in the middle of the it. Bessie wonders: how far is it to walk around that grove and get back to my starting …