#include<stdio.h>
#include<algorithm>
using namespace std;
int main(){
	int a;scanf("%d",&a);
	for(int i=a-100;i<=a+100;i++){
		if(i<2)continue;
		bool ok=false;
		for(int j=2;j*j<=i;j++)if(i%j==0)ok=true;
		if(ok){
			printf("%d\n",i);return 0;
		}
	}
}