#include "iostream"
using namespace std;

int main() {
    int n;
    cin>>n;
    for (int i = n-100; i <n+101 ; ++i) {
        for (int j = 2; j < i / 2+1; ++j) {
            if (i%j==0) {
                cout<<i<<endl;
                return 0;
            }
        }
    }
    return 0;
}