题目：
BH is in a maze,the maze is a matrix,he wants to escape!
输入
The input consists of multiple test cases.
For each case,the first line contains 2 integers N,M( 1 <= N, M <= 100 ).
Each of the following N lines contain M characters. Each charac
题目：
BH is in a maze,the maze is a matrix,he wants to escape!
输入
The input consists of multiple test cases.
For each case,the first line contains 2 integers N,M( 1 <= N, M <= 100 ).
Each of the following N lines contain M characters. Each charac
