B'Consider the following process. You have a binary string (a string where each character is either 0 or 1) w of length n and an integer x . You build a new binary string s consisting of n characters. The i -th character of s is chosen as follows: You are given the integer x and the resulting string s . Reconstruct the original string w . The first line contains one integer t ( 1 <= t <= 1000 ) -- the number of test cases. Each test case consists of two lines. The first line contains the resulting string s ( 2 <= |s| <= 10^5 , each character of s is either 0 or 1). The second line contains one integer x ( 1 <= x <= |s| - 1 ). The total length of all strings s in the input does not exceed 10^5 . For each test case, print the answer on a separate line as follows: '...