#include<bits/stdc++.h>
using namespace std;
int main(){
	int a;
	cin>>a;
	if(a%3==2||a%5==3||a%7==2) cout<<a;
	return 0;
}
/**************************************************************
	Problem: 1021
	User: lijinkai
	Language: C++
	Result: Wrong Answer
****************************************************************/