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: Time Limit Exceeded)

import scala.io.StdIn._

object Main extends App {


  val x = readInt()

  def solve(): Int = {
    var ans = x
    while(!isPrime(x)) ans += 1
    ans
  }

  def isPrime(num: Int): Boolean = {
    if(num <= 1) false
    else if(num == 2) true
    else !(2 until num).exists(num % _ == 0)
  }

  println(solve())

}