You are given n integer numbers a_1, a_2, ..., a_n. Consider graph on n nodes, in which nodes i, j (i≠ j) are connected if and only if, a_i AND a_j≠ 0, where AND denotes the [bitwise AND operation](https://en.wikipedia.org/wiki/Bitwise_operation#AND).

Find the length of the shortest cycle in this graph or determine that it doesn't have cycles at all.

Input

The first line contains one integer n (1 ≤ n ≤ 10^5) — number of numbers.

The second line contains n integer numbers a_1, a_2, ..., a_n (0 ≤ a_i ≤ 10^{18}).

Output

If the graph doesn't have any cycles, output -1. Else output the length of the shortest cycle.

Examples

Input


4
3 6 28 9


Output


4

Input


5
5 12 9 16 48


Output


3

Input


4
1 2 4 8


Output


-1

Note

In the first example, the shortest cycle is (9, 3, 6, 28).

In the second example, the shortest cycle is (5, 12, 9).

The graph has no cycles in the third example.
#include <bits/stdc++.h>
using namespace std;
using ll = std::int_fast64_t;
using P = pair<ll, ll>;
constexpr ll inf = 1000000000;
constexpr ll mod = 998244353;
constexpr long double eps = 1e-15;
template <typename T1, typename T2>
ostream& operator<<(ostream& os, pair<T1, T2> p) {
  os << to_string(p.first) << " " << to_string(p.second);
  return os;
}
template <typename T>
ostream& operator<<(ostream& os, vector<T>& v) {
  for (ll i = 0; i < (int)v.size(); i++) {
    if (i) os << " ";
    os << to_string(v[i]);
  }
  return os;
}
struct modint {
  ll n;

 public:
  modint(const ll n = 0) : n((n % mod + mod) % mod) {}
  static modint pow(modint a, int m) {
    modint r = 1;
    while (m > 0) {
      if (m & 1) {
        r *= a;
      }
      a = (a * a);
      m /= 2;
    }
    return r;
  }
  modint& operator++() {
    *this += 1;
    return *this;
  }
  modint& operator--() {
    *this -= 1;
    return *this;
  }
  modint operator++(int) {
    modint ret = *this;
    *this += 1;
    return ret;
  }
  modint operator--(int) {
    modint ret = *this;
    *this -= 1;
    return ret;
  }
  modint operator~() const { return (this->pow(n, mod - 2)); }
  friend bool operator==(const modint& lhs, const modint& rhs) {
    return lhs.n == rhs.n;
  }
  friend bool operator<(const modint& lhs, const modint& rhs) {
    return lhs.n < rhs.n;
  }
  friend bool operator>(const modint& lhs, const modint& rhs) {
    return lhs.n > rhs.n;
  }
  friend modint& operator+=(modint& lhs, const modint& rhs) {
    lhs.n += rhs.n;
    if (lhs.n >= mod) lhs.n -= mod;
    return lhs;
  }
  friend modint& operator-=(modint& lhs, const modint& rhs) {
    lhs.n -= rhs.n;
    if (lhs.n < 0) lhs.n += mod;
    return lhs;
  }
  friend modint& operator*=(modint& lhs, const modint& rhs) {
    lhs.n = (lhs.n * rhs.n) % mod;
    return lhs;
  }
  friend modint& operator/=(modint& lhs, const modint& rhs) {
    lhs.n = (lhs.n * (~rhs).n) % mod;
    return lhs;
  }
  friend modint operator+(const modint& lhs, const modint& rhs) {
    return modint(lhs.n + rhs.n);
  }
  friend modint operator-(const modint& lhs, const modint& rhs) {
    return modint(lhs.n - rhs.n);
  }
  friend modint operator*(const modint& lhs, const modint& rhs) {
    return modint(lhs.n * rhs.n);
  }
  friend modint operator/(const modint& lhs, const modint& rhs) {
    return modint(lhs.n * (~rhs).n);
  }
};
istream& operator>>(istream& is, modint m) {
  is >> m.n;
  return is;
}
ostream& operator<<(ostream& os, modint m) {
  os << m.n;
  return os;
}
long long extgcd(long long a, long long b, long long& x, long long& y) {
  long long d = a;
  if (b != 0) {
    d = extgcd(b, a % b, y, x);
    y -= (a / b) * x;
  } else {
    x = 1;
    y = 0;
  }
  return d;
}
long long mod_inverse(long long a, long long m) {
  long long x, y;
  if (extgcd(a, m, x, y) == 1)
    return (m + x % m) % m;
  else
    return -1;
}
vector<long long> fact(3030303 + 1, inf);
long long mod_fact(long long n, long long& e) {
  if (fact[0] == inf) {
    fact[0] = 1;
    if (3030303 != 0) fact[1] = 1;
    for (ll i = 2; i <= 3030303; ++i) {
      fact[i] = (fact[i - 1] * i) % mod;
    }
  }
  e = 0;
  if (n == 0) return 1;
  long long res = mod_fact(n / mod, e);
  e += n / mod;
  if ((n / mod) % 2 != 0) return (res * (mod - fact[n % mod])) % mod;
  return (res * fact[n % mod]) % mod;
}
long long mod_comb(long long n, long long k) {
  if (n < 0 || k < 0 || n < k) return 0;
  long long e1, e2, e3;
  long long a1 = mod_fact(n, e1), a2 = mod_fact(k, e2),
            a3 = mod_fact(n - k, e3);
  if (e1 > e2 + e3) return 0;
  return (a1 * mod_inverse((a2 * a3) % mod, mod)) % mod;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector<ll> a;
  for (ll i = 0; i < (int)n; i++) {
    ll tmp;
    cin >> tmp;
    if (tmp) a.push_back(tmp);
  }
  n = (int)a.size();
  if (n >= 200) {
    cout << 3 << endl;
    return 0;
  }
  vector<vector<int>> g(n);
  for (ll i = 0; i < (int)n; i++) {
    for (ll j = 0; j < (int)n; j++) {
      if (i == j) continue;
      if ((a[i] & a[j]) != 0) g[i].push_back(j);
    }
  }
  int ans = inf;
  for (ll i = 0; i < (int)n; i++) {
    vector<int> d(n, inf);
    d[i] = 0;
    queue<pair<int, int>> q;
    q.push({i, -1});
    while (!q.empty()) {
      int pos = q.front().first, par = q.front().second;
      q.pop();
      for (ll j = 0; j < (int)g[pos].size(); j++) {
        if (g[pos][j] == par) continue;
        if (d[g[pos][j]] == inf) {
          d[g[pos][j]] = d[pos] + 1;
          q.push({g[pos][j], pos});
        } else {
          ans = min(ans, d[pos] + d[g[pos][j]] + 1);
        }
      }
    }
  }
  if (ans == inf)
    cout << -1 << endl;
  else
    cout << ans << endl;
  return 0;
}
