题目描述

You are to find all the two-word compound words in a dictionary. A two-word compound word is a word in the dictionary that is the concatenation of exactly two other words in the dictionary.

输入要求

Standard input consists of a number of lowercase words, one per line, in alphabetical order. There will be no more than 120,000 words.

输出要求

Your output should contain all the compound words, one per line, in alphabetical order.

输入样例

a
alien
born
less
lien
never
nevertheless
new
newborn
the
zebra

输出样例

alien
newborn

提示

来源

University of Waterloo Local Contest 1996.09.28