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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(arr:Array<String>) {
    val x = readLine()!!.toInt()
    val ans = getPrimeList().filter { it >= x }.min()!!
    println(ans)
}

fun getPrimeList():List<Int> {
    val arr = BooleanArray(200000)
    val list = mutableListOf<Int>()
    for(i in (2 until arr.size)) {
        if(arr[i]) {
            continue
        }
        list.add(i)
        for(j in (1 until  arr.size)) {
            if(i * j >= arr.size) {
                break
            }
            arr[i*j] = true
        }
    }
    return list
}