Solve the programming task below in a Python markdown code block.
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You are given a range of integers $\{L, L+1, \ldots, R\}$. An integer $X$ is said to be *reachable* if it can be represented as a sum of two not necessarily distinct integers in this range. Find the number of distinct reachable integers.

------  Input ------
The first line of the input contains a single integer $T$ denoting the number of test cases. The description of $T$ test cases follows.
The first and only line of each test case contains two space-separated integers $L$ and $R$.

------  Output ------
For each test case, print a single line containing one integer — the number of reachable integers.

------  Constraints ------
$1 ≤ T ≤ 10^{5}$
$1 ≤ L ≤ R ≤ 10^{6}$

----- Sample Input 1 ------ 
2

2 2

2 3
----- Sample Output 1 ------ 
1

3
----- explanation 1 ------ 
Example case 1: The only reachable integer is $2 + 2 = 4$.

Example case 2: $4$, $5$ and $6$ are reachable, since $2+2=4$, $2+3=5$ and $3+3=6$.