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) {
      Scanner sc = new Scanner(System.in);
      int X = sc.nextInt();
      int prime = X;
      int mid = prime/2;
      boolean flag = false;
      while (true){
        for(int i = 2; i <= mid; ++i){
        	if(prime % i == 0)
            {
              flag = true;
              break;
            }
        }
        if (!flag){
          break;
        }
        else
          flag = false;
          prime++;
      }
      System.out.println(prime);
    }
}