B"For the given integer n ( n > 2 ) let's write down all the strings of length n which contain n-2 letters 'a' and two letters 'b' in lexicographical (alphabetical) order. Recall that the string s of length n is lexicographically less than string t of length n , if there exists such i ( 1 <= i <= n ), that s_i < t_i , and for any j ( 1 <= j < i ) s_j = t_j . The lexicographic comparison of strings is implemented by the operator < in modern programming languages. For example, if n=5 the strings are (the order does matter): It is easy to show that such a list of strings will contain exactly frac{n cdot (n-1)}{2} strings. You are given n ( n > 2 ) and k ( 1 <= k <= frac{n cdot (n-1)}{2} ). Print the k -th string from the list. The input contains one or more test cases. The first line contains one integer t ( 1 <= t <= 10^4 ) -- the number of test cases in the test. Then t test cases follow. Each test case is written on the the separate line containing two integers n and k ( 3 <= n <= 10^5, 1 <= k <= min(2 cdot10^9, frac{n cdot (n-1)}{2}) . The sum of values n over all test cases in the test doesn't exceed 10^5 . For each test case print the k -th string from the list of all described above strings of length n . Strings in the list are sorted lexicographically (alphabetically). "...