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;
import java.util.HashMap;
import java.util.TreeMap;
import java.util.Map;
import java.util.Collections;
import java.util.List;
import java.util.Arrays;
import java.util.ArrayList;
import java.lang.Math;

public class Main {

    private static Scanner sc = new Scanner(System.in);
    private static int mod = (int) 10e8 + 7;

    public static void main(String[] args) {
        int n = sc.nextInt();
        for (int i = n; i <= Integer.MAX_VALUE; i++) {
            boolean isPrime = true;
            for (int j = 2; j < Math.sqrt(i); j++) {
                if (i%j == 0) {
                    isPrime = false;
                    break;
                }
            }
            if(isPrime) {
                System.out.println(i);
                return;
            }
        }
    }

}