Description: You are given two integers $$$l$$$ and $$$r$$$, $$$l\le r$$$. 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, $$$26 \bmod 8 = 2$$$. Input Format: Each test contains multiple test cases. The first line contains one positive integer $$$t$$$ $$$(1\le t\le 10^4)$$$, denoting the number of test cases. Description of the test cases follows. The only line of each test case contains two integers $$$l$$$, $$$r$$$ ($$$1\le l \le r \le 10^9$$$). Output Format: For every test case, output the largest possible value of $$$a \bmod b$$$ over all pairs $$$(a, b)$$$ of integers for which $$$r\ge a \ge b \ge l$$$. Note: 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 $$$a \bmod b = 1$$$.