#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <functional>
#include <set>
#include <sstream>
#include <map>
#include <queue>
#include <stack>

using namespace std;

typedef vector<double> vec;
typedef vector<vec> mat;

int main()
{
	long long n;
	cin>>n;
	set<long long> s;
	for(long long i=2;i*i<=n;i++){
		if(n%i==0){
			s.insert(i);
			s.insert(n/i);
		}
	}

	s.erase(2);
	s.erase(1);
	s.insert(n);
	cout<<*s.begin()<<endl;	
    return 0;
}