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.Scanner;
 
public class Main {
	public static void main(String[] args) {
		try (Scanner scn = new Scanner(System.in)) {
			int x = scn.nextInt();
			int ret;
			while(true){
			    if(isPrimeNum(x)){
			    ret = x;
			    break;    
			    }
			    x++;
			}
			
		
			System.out.println(ret);
		}
	}
	
    static boolean isPrimeNum(int num){
	    if(num==2) return true;
	   if(num % 2 == 0) return false;
	   for(int i = 2;i<num;i++){
	       if(num % i == 0) return false;
	   }
	    
	    return true;
	    
	}
}