题目描述
You are given two integers $x$ and $y$ (it is guaranteed that $x > y$). You may choose any prime integer $p$ and subtract it any number of times from $x$. Is it possible to make $x$ equal to $y$?
Recall that a prime number is a positive integer that has exactly two positive divisors: $1$ and this integer itself. The sequence of prime numbers starts with $2$, $3$, $5$, $7$, $11$.
Your program should solve $t$ independent test cases.
Input
The first line contains one integer $t$ ($1 \le t \le 1000$) — the number of test cases.
Then $t$ lines follow, each describing a test case. Each line contains two integers $x$ and $y$ ($1 \le y < x \le 10^{18}$).
Output
For each test case, print YES if it is possible to choose a prime number $p$ and subtract it any number of times from $x$ so that $x$ becomes equal to $y$. Otherwise, print NO.
You may print every letter in any case you want (so, for example, the strings yEs, yes, Yes, and YES will all be recognized as positive answer).
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
In the first test of the example you may choose $p = 2$ and subtract it once.
In the second test of the example you may choose $p = 5$ and subtract it twice. Note that you cannot choose $p = 7$, subtract it, then choose $p = 3$ and subtract it again.
In the third test of the example you may choose $p = 3$ and subtract it $333333333333333333$ times.