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);
    int x = sc.nextInt();
    if(x==1){
      System.out.println(2);
      System.exit(0);
    }
    if(x==2){
      System.out.println(2);
      System.exit(0);
    }
    if(x%2==0){
      x +=1;
    }

    while(true){
      int count = 0;

      for(int i=3; i<x;i+=2){
        if(x%i==0){
          count += 1;
        }
      }
      if(count==0){
        break;
      }else{
        x +=2;
      }
    }
    System.out.println(x);


  }
}