Acm, a treasure-explorer, is exploring again. This time he is in a special maze, in which there are some doors (at most 5 doors, represented by 'A', 'B', 'C', 'D', 'E' respectively). In order to find the treasure, Acm may need to open doors. However, to open a door he needs to find all the door's keys (at least one) in the maze first. For example, if there are 3 keys of Door A, to open the door he should find all the 3 keys first (that's three 'a's which denote the keys of 'A' in the maze). Now make a program to tell Acm whether he can find the treasure or not. Notice that Acm can only go up, down, left and right in the maze.输入描述 The input consists of multiple test cases. The first line of each test case contains two integers M an输出描述 For each test case, in one line output "YES" if Acm can find the treasure, or "NO" otherwise.输入例子 4 4 S.X. a.X. ..XG .... 3 4 S.Xa .aXB b.AG 0 0 输出例子 YES NO