Problem:
Score: 300 points

Problem Statement

Find the minimum prime number greater than or equal to X.

Notes

A prime number is an integer greater than 1 that cannot be evenly divided by any positive integer except 1 and itself.

For example, 2, 3, and 5 are prime numbers, while 4 and 6 are not.

Constraints

2 \le X \le 10^5

All values in input are integers.

Input

Input is given from Standard Input in the following format:

X

Output

Print the minimum prime number greater than or equal to X.

Sample Input 1

20

Sample Output 1

23

The minimum prime number greater than or equal to 20 is 23.

Sample Input 2

2

Sample Output 2

2

X itself can be a prime number.

Sample Input 3

99992

Sample Output 3

100003

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
public class Main { 
    public static void main(String[] args) {
       Scanner sc=new Scanner(System.in);
       String o="";
       int a=sc.nextInt(); 
       if(a<=3){
         o=Integer.toString(a);
       }else{
      	while(a<=100003){
         int n=(int)Math.sqrt((double)a); 
         boolean end=false;
         for (int i=2;i<=n;i++){
              if(a%i==0){
                  break;
              }else if(i==n){
                  o=Integer.toString(a);
                	end=true;
                  break;
              }
            }
          if (end)break;
      	  a++;
    	}
       }
      System.out.println(o);
    }
}