Solve the programming task below in a Python markdown code block.
You are given two integers $l$ and $r$, $l\le r$. Find the largest possible value of $a mod b$ over all pairs $(a, b)$ of integers for which $r\ge a \ge b \ge l$.

As a reminder, $a mod b$ is a remainder we get when dividing $a$ by $b$. For example, $26 mod 8 = 2$.


-----Input-----

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-----

For every test case, output the largest possible value of $a mod b$ over all pairs $(a, b)$ of integers for which $r\ge a \ge b \ge l$.


-----Examples-----

Input
4
1 1
999999999 1000000000
8 26
1 999999999
Output
0
1
12
499999999


-----Note-----

In the first test case, the only allowed pair is $(a, b) = (1, 1)$, for which $a mod b = 1 mod 1 = 0$.

In the second test case, the optimal choice is pair $(a, b) = (1000000000, 999999999)$, for which $a mod b = 1$.