Solve the programming task below in a Python markdown code block.
Let's dive into the interesting topic of regular expressions! You are given some input, and you are required to check whether they are valid mobile numbers.  

A valid mobile number is a ten digit number starting with a $7,8$ or $9$.  

Concept

A valid mobile number is a ten digit number starting with a $7,8$ or $9$.  

Regular expressions are a key concept in any programming language. A quick explanation with Python examples is available here. You could also go through the link below to read more about regular expressions in Python.  

https://developers.google.com/edu/python/regular-expressions  

Input Format

The first line contains an integer $N$, the number of inputs.

$N$ lines follow, each containing some string.

Constraints  

$1\leq N\leq10$  

$2\leq len(Number)\leq15$  

Output Format

For every string listed, print "YES" if it is a valid mobile number and "NO" if it is not on separate lines. Do not print the quotes.

Sample Input
2
9587456281
1252478965

Sample Output
YES
NO