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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.util.*;

public class Main{
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    
    int n = sc.nextInt();
    boolean isPrime = false;
    
    for(int i = n; !isPrime; i++){
      boolean flg = true;
      
      for(int j = 2; flg && j <= Math.sqrt(n); j++){
        if(i % j == 0){
          flg = false;
        }
      }
      
      if(flg){
        System.out.println(i);
        isPrime = true;
      }
    }
  }
}