CF1367A.Short Substrings

Alice guesses the strings that Bob made for her.

At first, Bob came up with the secret string $a$ consisting of lowercase English letters. The string $a$ has a length of $2$ or more characters. Then, from string $a$ he builds a new string $b$ and offers Alice the string $b$ so that she can guess the string $a$.

Bob builds $b$ from $a$ as follows: he writes all the substrings of length $2$ of the string $a$ in the order from left to right, and then joins them in the same order into the string $b$.

For example, if Bob came up with the string $a$="abac", then all the substrings of length $2$ of the string $a$ are: "ab", "ba", "ac". Therefore, the string $b$="abbaac".

You are given the string $b$. Help Alice to guess the string $a$ that Bob came up with. It is guaranteed that $b$ was built according to the algorithm given above. It can be proved that the answer to the problem is unique.

爱丽丝需要猜出鲍勃为她构造的字符串。

首先，鲍勃构思了一个由小写英文字母组成的秘密字符串 $a$。字符串 $a$ 的长度至少为 $2$。接着，鲍勃根据字符串 $a$ 构造出一个新的字符串 $b$，并将字符串 $b$ 提供给爱丽丝，让她据此推断出原始字符串 $a$。

鲍勃按如下方式从 $a$ 构造 $b$：他将字符串 $a$ 中所有长度为 $2$ 的子串按从左到右的顺序依次写出，再将这些子串按相同顺序连接起来，形成字符串 $b$。

例如，若鲍勃构思的字符串 $a$ 为 "abac"，则 $a$ 中所有长度为 $2$ 的子串依次为："ab"、"ba"、"ac"。因此，字符串 $b$ = "abbaac"。

现给出字符串 $b$，请帮助爱丽丝推断出鲍勃所构思的字符串 $a$。题目保证 $b$ 是严格按照上述算法生成的，且该问题的答案唯一。

The first line contains a single positive integer $t$ ($1 \le t \le 1000$) — the number of test cases in the test. Then $t$ test cases follow.

Each test case consists of one line in which the string $b$ is written, consisting of lowercase English letters ($2 \le |b| \le 100$) — the string Bob came up with, where $|b|$ is the length of the string $b$. It is guaranteed that $b$ was built according to the algorithm given above.

第一行包含一个正整数 $t$（$1 \le t \le 1000$），表示测试用例的数量。随后是 $t$ 个测试用例。

每个测试用例由一行组成，该行包含字符串 $b$，其由小写英文字母构成（$2 \le |b| \le 100$），即 Bob 构造出的字符串，其中 $|b|$ 表示字符串 $b$ 的长度。保证 $b$ 是根据上述算法构造而成的。

Output $t$ answers to test cases. Each answer is the secret string $a$, consisting of lowercase English letters, that Bob came up with.

输出 $t$ 个测试用例的答案。每个答案均为 Bob 构造的密钥字符串 $a$，该字符串由小写英文字母组成。

The first test case is explained in the statement.

In the second test case, Bob came up with the string $a$="ac", the string $a$ has a length $2$, so the string $b$ is equal to the string $a$.

In the third test case, Bob came up with the string $a$="bcdaf", substrings of length $2$ of string $a$ are: "bc", "cd", "da", "af", so the string $b$="bccddaaf".

第一个测试用例在题目描述中已作解释。

在第二个测试用例中，Bob 构造的字符串 $a$ 为 "ac"，字符串 $a$ 的长度为 $2$，因此字符串 $b$ 等于字符串 $a$。

在第三个测试用例中，Bob 构造的字符串 $a$ 为 "bcdaf"，字符串 $a$ 的所有长度为 $2$ 的子串为："bc"、"cd"、"da"、"af"，因此字符串 $b$ = "bccddaaf"。