Input Format
The first line contains space-separated integers  (rows) and  (columns) respectively.
The next  lines contain the row elements of the matrix script.
Constraints
Note: A  score will be awarded for using 'if' conditions in your code.
Output Format
Print the decoded matrix script.

### Problem solution in python 2 programming language.

import re
matrix = []
N,M = map(int, raw_input().split())
for i in range(N):
matrix.append(list(raw_input()))
print re.sub(r'(?<=[A-Za-z0-9])([^A-Za-z0-9]+)(?=[A-Za-z0-9])',' ',"".join("".join(decode) for decode in zip(*matrix)))

### Problem solution in python 3 programming language.

import math
import os
import random
import re
import sys
first_multiple_input = input().rstrip().split()
n = int(first_multiple_input[0])
m = int(first_multiple_input[1])
matrix = []
for _ in range(n):
matrix_item = input()
matrix.append(matrix_item)
encoded_string = "".join([matrix[j][i] for i in range(m) for j in range(n)])
pat = r'(?<=[a-zA-Z0-9])[^a-zA-Z0-9]+(?=[a-zA-Z0-9])'
print(re.sub(pat,' ',encoded_string))