B'You are given a string s consisting of the characters '0 ', '1 ', and '? '. You need to replace all the characters with '? ' in the string s by '0 ' or '1 ' so that the string becomes a palindrome and has exactly a characters '0 ' and exactly b characters '1 '. Note that each of the characters '? ' is replaced independently from the others. A string t of length n is called a palindrome if the equality t[i] = t[n-i+1] is true for all i ( 1 <= i <= n ). For example, if s= "01?????0", a=4 and b=4 , then you can replace the characters '? ' in the following ways: For the given string s and the numbers a and b , replace all the characters with '? ' in the string s by '0 ' or '1 ' so that the string becomes a palindrome and has exactly a characters '0 ' and exactly b characters '1 '. The first line contains a single integer t ( 1 <= t <= 10^4 ). Then t test cases follow. The first line of each test case contains two integers a and b ( 0 <= a, b <= 2 cdot 10^5 , a + b ge 1 ). The second line of each test case contains the string s of length a+b , consisting of the characters '0 ', '1 ', and '? '. It is guaranteed that the sum of the string lengths of s over all test cases does not exceed 2 cdot 10^5 . For each test case, output: If there are several suitable ways to replace characters, you can output any. '...