#include <bits/stdc++.h>
#define GET_MACRO(a, b, c, NAME, ...) NAME
#define rep(...) GET_MACRO(__VA_ARGS__, rep3, rep2)(__VA_ARGS__)
#define rep2(i, a) rep3 (i, 0, a)
#define rep3(i, a, b) for (int i = (a); i < (b); i++)
#define repr(...) GET_MACRO(__VA_ARGS__, repr3, repr2)(__VA_ARGS__)
#define repr2(i, a) repr3 (i, 0, a)
#define repr3(i, a, b) for (int i = (b) - 1; i >= (a); i--)
template<class T1, class T2> inline bool chmin(T1 &a, T2 b) { return b < a && (a = b, true); }
template<class T1, class T2> inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
using namespace std;
typedef long long ll;

vector<ll> divisor(ll n) {
	vector<ll> res;
	for (ll i = 1; i * i <= n; i++) {
		if (n % i == 0) {
			res.push_back(i);
			if (i != n / i) res.push_back(n / i);
		}
	}
	sort(res.begin(), res.end());
	return res;
}

int main() {
	ll n;
	cin >> n;
	auto ds = divisor(n);
	while (ds.front() <= 2) ds.erase(ds.begin(), ds.begin() + 1);
	cout << ds[0] << endl;
	return 0;
}