1.该OJ由于交换空间受限,暂不不支持万能头文件:bits/stdc++.h!!! 2.该OJ如果是长整型的话,C的输入输出请使用%lld!!!

Problem 1010. -- Biggest Number

1010: Biggest Number

Time Limit: 1 Sec  Memory Limit: 128 MB
Submit: 0  Solved: 0
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Description

You have a maze with obstacles and non-zero digits in it:

 

 

You can start from any square, walk in the maze, and finally stop at some square. Each step, you may only walk into one of the four neighbouring squares (up, down, left, right) and you cannot walk into obstacles or walk into a square more than once. When you finish, you can get a number by writing down the digits you encounter in the same order as you meet them. For example, you can get numbers 9784, 4832145 etc. The biggest number you can get is 791452384, shown in the picture above.

 

Your task is to find the biggest number you can get.

 

Input

There will be at most 25 test cases. Each test begins with two integers R and C (2<=R,C<=15, R*C<=30), the number of rows and columns of the maze. The next R rows represent the maze. Each line contains exactly C characters (without leading or trailing spaces), each of them will be either '#' or one of the nine non-zero digits. There will be at least one non-obstacle squares (i.e. squares with a non-zero digit in it) in the maze. The input is terminated by a test case with R=C=0, you should not process it.

 

Output

For each test case, print the biggest number you can find, on a single line.

Input

Output

Sample Input

3 7
##9784#
##123##
##45###
0 0

Sample Output

791452384

HINT

Source

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