!/bin/python3

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)

matrix = list(zip(*matrix))

sample = str()

for words in matrix: for char in words: sample += char

print(re.sub(r'(?<=\w)([^\w\d]+)(?=\w)', ' ', sample))