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) {
    // TODO 自動生成されたメソッド・スタブ
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();

    for (int i = n; i <= 1000000; i++) {
      int amari_count = 0;
      boolean isFound = true;
      for (int j = 1; j <= i; j++) {
        if (i % j == 0) {
          amari_count++;
        }
        if (amari_count > 2) {
          isFound = false;
          break;
        }
      }
      if (isFound) {
        System.out.println(i);
        break;
      }
    }
  }
}