#!/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])
s = ''

matrix = []

for _ in range(n):
    matrix_item = input()
    matrix.append(matrix_item)

    
s = [''.join(matrix[row][item]) for item in range(0,m) for row in range(0,n)]
print(re.sub(r"(?<=\w)(\W+)(?=\w)", " ", ''.join(s)))