package Yukicoder

/**
 * Created by hichikawa on 2015/11/11.
 */
fun main(args: Array<String>) {
    fun readLineLong() : Long {
        val str = readLine() as String
        return str.toLong()
    }

    val  num = readLineLong()
    if (num != 2.toLong() && num % 2.toLong() == 0.toLong()) {
        println(num)
        return
    }

    val min = Math.max(4, num - 100)
    for (i in min..(num+100)) {
        if (i.toInt() % 2 == 0) {
            println(i)
            break
        }
        for (j in 3..(i-1) step 2) {
            if (i.toInt() % j.toInt() == 0) {
                println(i)
                break
            }
        }
    }
}