Square Difference

Description:

Input:

The first line contains a number $$$t$$$ ($$$1 \leq t \leq 5$$$) — the number of test cases.

Each of the next $$$t$$$ lines describes the $$$i$$$-th test case. It contains two integers $$$a$$$ and $$$b~(1 \leq b < a \leq 10^{11})$$$ — the side length of Alice's square and the side length of the square that Bob wants.

Output:

Print $$$t$$$ lines, where the $$$i$$$-th line is the answer to the $$$i$$$-th test case. Print "YES" (without quotes) if the area of the remaining piece of cloth is prime, otherwise print "NO".

You can print each letter in an arbitrary case (upper or lower).

Sample Input:

4
6 5
16 13
61690850361 24777622630
34 33

Sample Output:

YES
NO
NO
YES

Note:

The figure below depicts the first test case. The blue part corresponds to the piece which belongs to Bob, and the red part is the piece that Alice keeps for herself. The area of the red part is $$$6^2 - 5^2 = 36 - 25 = 11$$$, which is prime, so the answer is "YES".

In the second case, the area is $$$16^2 - 13^2 = 87$$$, which is divisible by $$$3$$$.

In the third case, the area of the remaining piece is $$$61690850361^2 - 24777622630^2 = 3191830435068605713421$$$. This number is not prime because $$$3191830435068605713421 = 36913227731 \cdot 86468472991 $$$.

In the last case, the area is $$$34^2 - 33^2 = 67$$$.