n = int(input()) check = [0] * 26 for _ in range(n): s = input().split() i, ans = 0, False for i in range(len(s)): if not check[ord(s[i][0].lower()) - 97]: check[ord(s[i][0].lower()) - 97] = 1 s[i] = '[' + s[i][0] + ']' + s[i][1:] ans = True break if ans: print(' '.join(s)) continue s = ' '.join(s) for i, c in enumerate(s): if c != ' ' and not check[ord(c.lower()) - 97]: check[ord(c.lower()) - 9..