4864: P7645 [COCI2012-2013#5] ARHIPELAG(普及-)
Memory Limit:128 MB
Time Limit:1.000 S
Judge Style:Text Compare
Creator:
Submit:1
Solved:1
Description
Input

Output

Sample Input Copy
5 3
...
.X.
.X.
.X.
...
Sample Output Copy
X
HINT
