Forbidden Subsequence
Description
You are given strings $S$ and $T$, consisting of lowercase English letters. It is guaranteed that $T$ is a permutation of the string abc.
Find string $S'$, the lexicographically smallest permutation of $S$ such that $T$ is not a subsequence of $S'$.
String $a$ is a permutation of string $b$ if the number of occurrences of each distinct character is the same in both strings.
A string $a$ is a subsequence of a string $b$ if $a$ can be obtained from $b$ by deletion of several (possibly, zero or all) elements.
A string $a$ is lexicographically smaller than a string $b$ if and only if one of the following holds:
- $a$ is a prefix of $b$, but $a \ne b$;
- in the first position where $a$ and $b$ differ, the string $a$ has a letter that appears earlier in the alphabet than the corresponding letter in $b$.
Each test contains multiple test cases. The first line contains a single integer $t$ ($1 \le t \le 1000$) — the number of test cases. Description of the test cases follows.
The first line of each test case contains a string $S$ ($1 \le |S| \le 100$), consisting of lowercase English letters.
The second line of each test case contains a string $T$ that is a permutation of the string abc. (Hence, $|T| = 3$).
Note that there is no limit on the sum of $|S|$ across all test cases.
For each test case, output a single string $S'$, the lexicographically smallest permutation of $S$ such that $T$ is not a subsequence of $S'$.
Input
Each test contains multiple test cases. The first line contains a single integer $t$ ($1 \le t \le 1000$) — the number of test cases. Description of the test cases follows.
The first line of each test case contains a string $S$ ($1 \le |S| \le 100$), consisting of lowercase English letters.
The second line of each test case contains a string $T$ that is a permutation of the string abc. (Hence, $|T| = 3$).
Note that there is no limit on the sum of $|S|$ across all test cases.
Output
For each test case, output a single string $S'$, the lexicographically smallest permutation of $S$ such that $T$ is not a subsequence of $S'$.
Samples
7
abacaba
abc
cccba
acb
dbsic
bac
abracadabra
abc
dddddddddddd
cba
bbc
abc
ac
abc
aaaacbb
abccc
bcdis
aaaaacbbdrr
dddddddddddd
bbc
ac
Note
In the first test case, both aaaabbc and aaaabcb are lexicographically smaller than aaaacbb, but they contain abc as a subsequence.
In the second test case, abccc is the smallest permutation of cccba and does not contain acb as a subsequence.
In the third test case, bcdis is the smallest permutation of dbsic and does not contain bac as a subsequence.