A. The Miracle and the Sleeper
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

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

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 $$$a \bmod b$$$ over all pairs $$$(a, b)$$$ of integers for which $$$r\ge a \ge b \ge l$$$.

Example
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 $$$a \bmod b = 1 \bmod 1 = 0$$$.

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