#!/usr/bin/env python
#coding:utf8

def read():
    return input()


def isComposite(n):
    for i in range(2, n):
        if n % i == 0:
            return True
    return False


def work(N):
    for i in range(N - 100, N + 101):
        if isComposite(i):
            print i
            break


if __name__ == "__main__":
    work(read())