#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>

typedef long long ll;

int main(void)
{
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(2);
  ll n;
  std::cin >> n;
  ll sums = n * (n+1) / 2;
  std::vector< ll > divisible;
  for (ll i = 1; i * i <= n; ++i) {
    if (n%i!=0) continue;
    ll x = n/i;
    divisible.push_back(i);
    divisible.push_back(x);
  }
  std::sort(divisible.begin(), divisible.end(), std::greater< ll >());
  for (auto d : divisible) {
    if (sums%d==0) {std::cout << d << std::endl; return 0;}
  }
  return 0;
}