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)

object Main extends App {
  import scala.io.StdIn._
  def is_prime(p: Long):Boolean={
    if(p<=1) return false
    for {i <- 2L to(p) if(i * i <= p)} {
      if (p % i == 0) return false
    }
    return true
  }
  val x = readLong()
  var p = x
  while (!is_prime(p)) p+=1
  println(p)
}