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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

'use strict'


const check = (n) => {
  if (n < 1) return false
  let sqrt = Math.floor(Math.sqrt(n))
  for(var i = 2; i <= sqrt; ++i) {
    if(n % i === 0) return false
  }
  return true
}  

function Main(input) {
  input = parseInt(input.trim())

  while(true) {
    input += 1
    if(check(input)) {
      console.log(input)
      return
    }
  }

}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));