CF762C.Two strings

You are given two strings a and b. You have to remove the minimum possible number of consecutive (standing one after another) characters from string b in such a way that it becomes a subsequence of string a. It can happen that you will not need to remove any characters at all, or maybe you will have to remove all of the characters from b and make it empty.

Subsequence of string s is any such string that can be obtained by erasing zero or more characters (not necessarily consecutive) from string s.

给你两个字符串 $a$ 和 $b$。你需要从字符串 $b$ 中最少删除多少个连续的（彼此相邻的）字符，使得剩余的 $b$ 成为字符串 $a$ 的一个子序列。有可能你完全不需要删除任何字符，也有可能你需要删去 $b$ 中的所有字符，使其变为空串。

字符串 $s$ 的子序列是指：通过从 $s$ 中删除零个或多个字符（不一定是连续的） 所能得到的任意字符串。

The first line contains string a, and the second line — string b. Both of these strings are nonempty and consist of lowercase letters of English alphabet. The length of each string is no bigger than 105 characters.

第一行包含字符串 $a$，第二行包含字符串 $b$。这两个字符串均非空，且仅由小写英文字母组成。每个字符串的长度均不超过 $10^5$ 个字符。

On the first line output a subsequence of string a, obtained from b by erasing the minimum number of consecutive characters.

If the answer consists of zero characters, output «-» (a minus sign).

在第一行输出字符串 a 的一个子序列，该子序列由字符串 b 通过删除最少数量的连续字符得到。

如果答案为空（即包含零个字符），则输出 «-»（一个减号）。

In the first example strings a and b don't share any symbols, so the longest string that you can get is empty.

In the second example ac is a subsequence of a, and at the same time you can obtain it by erasing consecutive symbols cepted from string b.

在第一个例子中，字符串 $a$ 和 $b$ 不包含任何共同的字符，因此你能得到的最长字符串为空串。

在第二个例子中，$ac$ 是字符串 $a$ 的一个子序列，同时你也可以通过对字符串 $b$ 删除连续的子串 $cepted$ 得到它。