Problem O
Primality
                                            Given a positive integer $N$, determine whether it is prime or not.
Input
The first line contains the integer $N$ ($2 \le N \le 10^{18}$).
Output
Output YES if $N$ is prime, and NO otherwise.
Scoring
Your solution will be tested on a set of test groups, each worth a number of points. To get the points for a test group you need to solve all test cases in the test group.
| 
           Group  | 
        
           Points  | 
        
           Constraints  | 
      
| 
           $1$  | 
        
           $1$  | 
        
           $N \le 10^{16}$  | 
      
| 
           $2$  | 
        
           $1$  | 
        
           No additional constraints  | 
      
| Sample Input 1 | Sample Output 1 | 
|---|---|
          6  | 
        
          NO  | 
      
| Sample Input 2 | Sample Output 2 | 
|---|---|
          7  | 
        
          YES  | 
      
