B"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): Formally, you choose one of these two strings (let the chosen string be s ), then pick two integers l and r such that 1 <= l < r <= |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: 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 <= t <= 2000 ) -- the number of test cases. Each test case consists of two lines: Additional constraints on the input: 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. In the first test case, we can perform the following operations: In the second test case, the strings are already equal. In the third test case, we can perform the following operations: In the fourth and fifth test cases, it's impossible to make the given strings equal. "...