LR

This task is simple. You will be given $2$ positive integers $L$ and $R$.

Find the number of positive even integers $x$ such that $L \leq x \leq R$.

Input

The first line of input contains an integer $T$ denoting the number of test cases.

The only line of each test case contains two integers $L$ and $R$.

Constraints

$1 \le T \le 100$

$1 \leq L \leq R \leq 1000$

Output

Output one integer, the answer to the problem.

Sample

1
1 2

1