B'Sparkle gives you two arrays a and b of length n . Initially, your score is 0 . In one operation, you can choose an integer i and add a_i to your score. Then, you must set a_i = max(0, a_i - b_i) . You only have time to perform k operations before Sparkle sets off a nuclear bomb! What is the maximum score you can acquire after k operations? The first line contains t ( 1 <= q t <= q 1000 ) -- the number of test cases. The first line of each test case contains n and k ( 1 <= q n <= q 2 cdot 10^5, 1 <= q k <= q 10^9 ) -- the length of the arrays and the number of operations you can perform. The following line contains n integers a_1, a_2, ... a_n ( 1 <= q a_i <= q 10^9 ). The following line contains n integers b_1, b_2, ... b_n ( 1 <= q b_i <= q 10^9 ). It is guaranteed that the sum of n for all test cases does not exceed 2 cdot 10^5 . For each test case, output an integer, the maximum score you can acquire after k operations. '...