#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
template <typename T> using posteriority_queue = priority_queue<T, vector<T>, greater<T> >;
const int INF = 0x3f3f3f3f;
const ll LINF = 0x3f3f3f3f3f3f3f3fLL;
const double EPS = 1e-8;
const int MOD = 1000000007;
// const int MOD = 998244353;
const int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
const int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
template <typename T> void unique(vector<T> &a) { a.erase(unique(ALL(a)), a.end()); }
struct IOSetup {
  IOSetup() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  }
} iosetup;

using Int = ll;
// http://www.prefield.com/algorithm/math/jacobi.html
#define NEGPOW(e) ((e) % 2 ? -1 : 1)
Int jacobi(Int a, Int m) {
  if (a == 0) return m == 1 ? 1 : 0;
  if (a % 2)  return NEGPOW((a-1)*(m-1)/4)*jacobi(m%a, a);
  else        return NEGPOW((m*m-1)/8)*jacobi(a/2, m);
}

// https://oeis.org/A063988
int main() {
  int p, n; cin >> p >> n;
  cout << (n > 1 && jacobi(n, p) == -1 ? "1\n" : "-1\n");
  return 0;
}