#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <tuple>
#include <vector>
using namespace std;
using ll = int64_t;
#define rep(i, j, n) for (int i = j; i < (int)n; ++i)
#define rrep(i, j, n) for (int i = (int)n - 1; j <= i; --i)

template <typename T>
std::ostream& operator<<(std::ostream& os, std::vector<T>& a) {
  os << "{";
  for (size_t i = 0; i < a.size(); ++i) os << (i > 0 ? "," : "") << a[i];
  return os << "}";
}

constexpr ll MOD = 1000000007;
constexpr int INF = 0x3f3f3f3f;
constexpr ll INFL = 0x3f3f3f3f3f3f3f3fLL;

int main() {
  string s;
  cin >> s;
  if (s.size() > 16)
    cout << 1 << endl;
  else {
    ll n = atoll(s.c_str());
    ll i = 1;
    while (i * i <= n) {
      if (n % i == 0) {
        ll c = i;
        ll d = n / i;
        if ((c + d) % 2 == 0) {
          cout << 1 << endl;
          return 0;
        }
      }
      i++;
    }
  }
  cout << -1 << endl;
  return 0;
}