A16102 | Two Binary Strings

You are given two strings $a$ and $b$ of equal length, consisting of only characters 0 and/or 1; both strings start with character 0 and end with character 1.

You can perform the following operation any number of times (possibly zero):

- choose one of the strings and two equal characters in it; then turn all characters between them into those characters.

Formally, you choose one of these two strings (let the chosen string be $s$ ), then pick two integers $l$ and $r$ such that $1 \le l < r \le |s|$ and $s_l = s_r$ , then replace every character $s_i$ such that $l < i < r$ with $s_l$ .

For example, if the chosen string is 010101, you can transform it into one of the following strings by applying one operation:

- 000101 if you choose $l = 1$ and $r = 3$ ;
- 000001 if you choose $l = 1$ and $r = 5$ ;
- 010001 if you choose $l = 3$ and $r = 5$ ;
- 010111 if you choose $l = 4$ and $r = 6$ ;
- 011111 if you choose $l = 2$ and $r = 6$ ;
- 011101 if you choose $l = 2$ and $r = 4$ .

You have to determine if it's possible to make the given strings equal by applying this operation any number of times.

The first line contains a single integer $t$ ( $1 \le t \le 2000$ ) — the number of test cases.

Each test case consists of two lines:

- the first line contains the string $a$ ( $2 \le |a| \le 5000$ ), consisting of only characters 0 and/or 1.
- the second line contains the string $b$ ( $2 \le |b| \le 5000$ ), consisting of only characters 0 and/or 1.

Additional constraints on the input:

- in each test case, $|a| = |b|$ (the strings have equal length);
- in each test case, both strings start with 0 and end with 1;
- the total length of all strings $a$ in all test cases does not exceed $5000$ .

For each test case, print YES if it is possible to make the strings equal. Otherwise, print NO. You can print each letter in any register.