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 Scala (2.13.1) (judge verdict: Accepted)

import scala.io.StdIn.readInt

object Main extends App {
  val x = readInt()
  lazy val ys = 2 to (x / 2)
  
  def findPrime(x: Int): Int = {
    if (ys.exists(y => x % y == 0))
      findPrime(x + 1)
    else
      x
  }
  
  println(findPrime(x))
}