Recipe Card Shared Ingredient Tally

A test kitchen encodes each recipe card as a string of lowercase letters, where every letter represents one unit of a particular ingredient. A letter appearing twice in a card means the recipe calls for two units of that ingredient — for example, the card "aab" needs two units of ingredient a and one unit of ingredient b.

Given several recipe cards, find every ingredient unit that is common to all of the cards: a unit counts as common only if every single card contains at least that many units of the same letter. Each common unit must be listed as many times as it is guaranteed to appear across all of the cards.

Input format

Line 1: an integer n — the number of recipe cards. Next n lines: one lowercase string per line, the letters of that recipe card (1 <= length <= 100, only lowercase 'a'-'z', a card may repeat letters).

Output format

Print the common ingredient units as a single space-separated line, in non-decreasing alphabetical order (repeats of the same letter listed consecutively). If no unit is common to every card, print an empty line.

Constraints

1 <= n <= 100 1 <= length of each card <= 100 every card contains only lowercase English letters

3
bella
label
roller

e l l

2
cool
lock

c l o