#include<stdio.h>
main(){
    int N;
    scanf("%d",&N);
    for(int i = N-100;i <= N+100;i++){
        for(int j = 2;j < i;j++){
            if(i % j == 0){
//                printf("%d = %d * %d\n",i,j,i/j);//列挙
                printf("%d",i);
                return 0;
            }
        }
    }
}