import io.StdIn._
 
object Main extends App {
  val n = readInt
 
  require(2 <= n && n <= 100000)
 
  def isPrime(n: Int): Boolean = (2 until n).toList.forall(n % _ != 0)
 
  def minPrime(n: Int): Option[Int] = (n to 200000).find(isPrime)
 
  minPrime(n).map(println)
}