#include <bits/stdc++.h>
using namespace std;

template <typename T, typename U> bool cmin(T &a, U b) { return a > b && (a = b, true); }
template <typename T, typename U> bool cmax(T &a, U b) { return a < b && (a = b, true); }

signed main() {
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);

  int N;
  cin >> N;

  auto div = [&](long n) {
    vector<long> ret;
    for (long i = 1; i * i <= n; i++) {
      if (n % i == 0) {
        ret.push_back(i);
        if (i * i != n) ret.push_back(n / i);
      }
    }
    sort(begin(ret), end(ret));
    return ret;
  };

  cout << *next(div(N).rbegin()) << "\n";
}