B'You are given two integers l and r , l <= r . Find the largest possible value of a bmod b over all pairs (a, b) of integers for which r ge a ge b ge l . As a reminder, a bmod b is a remainder we get when dividing a by b . For example, 26 bmod 8 = 2 . Each test contains multiple test cases. The first line contains one positive integer t (1 <= t <= 10^4) , denoting the number of test cases. Description of the test cases follows. The only line of each test case contains two integers l , r ( 1 <= l <= r <= 10^9 ). For every test case, output the largest possible value of a bmod b over all pairs (a, b) of integers for which r ge a ge b ge l . In the first test case, the only allowed pair is (a, b) = (1, 1) , for which a bmod b = 1 bmod 1 = 0 . In the second test case, the optimal choice is pair (a, b) = (1000000000, 999999999) , for which a bmod b = 1 . '...