// No.312 置換処理
// https://yukicoder.me/problems/no/312
//

#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <utility>
using namespace std;

long long int solve(long long int N);
vector<long long int> calc_divisor(long long int n);


int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    long long N;
    cin >> N;
    long long ans = solve(N);
    cout << ans << endl;
}

long long int solve(long long int N) {
    vector<long long> divisors = calc_divisor(N);
    sort(divisors.begin(), divisors.end());

    for (auto d: divisors) {
        if (d > 2)
            return d;
    }
    return N;
}

vector<long long int> calc_divisor(long long int n) {
    vector<long long int> ans;
    for (long long i = 1; i * i <= n; ++i) {
        if (n % i == 0) {
            ans.push_back(i);
            if (n / i != i)
                ans.push_back(n / i);
        }
    }
    return ans;
}