408 help

#задача изи но я не понял
k,n = map(int,input().split())
a = []
ans = []
can = True
for i in range(n):
    a.append(input())


for word in a:
    i = 0
    left_count = 0
    right_count = len(word)
    left = True
    right = True
    for sym in word:
        if left:
            if sym == ' ':
                left_count += 1
            else:
                left = False
        else:
            if sym == ' ' and right:
                right_count = i
                right = False
            else:
                right = len(word)
                right = True
        i += 1
    wordx = word[left_count:right_count]
    right_count = left_count = 0
    len_word = len(wordx)
    while len_word < k:
        if left_count < right_count - 1:
            left_count += 1
            wordx = ' ' + wordx
        else:
            right_count += 1
            wordx += ' '
        len_word += 1
    if right_count - 1 == left_count:
        ans.append(wordx)
    else:
        can = False
        break

if can:
    for word in ans:
        print(word)
else:
    print('Impossible.')