func_code_string: #include <bits/stdc++.h>   using namespace std;   bool comp(int x, int y) { return x > y; }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     ;     int tt = 1;     long long m, n, k;     while (tt--) {       cin >> n >> k;       vector<int> vec(n);       for (long long i = 0; i < n; i++) {         cin >> vec[i];       };       sort(vec.begin(), vec.end());       set<int> s;       for (long long i = 0; i < n; i++) {         s.insert(vec[i]);       }       if (s.size() != n) {         cout << 0 << endl;       } else {         for (long long i = 0; i < n; i++) {           int no = vec[i] & k;           if (no == vec[i])             ;           if (no == vec[i] and               binary_search(vec.begin() + i + 1, vec.end(), no)) {             cout << 1 << endl;             return 0;           } else if (no != vec[i] and binary_search(vec.begin(), vec.end(), no)) {             cout << 1 << endl;             return 0;           }         }         s.clear();         for (long long i = 0; i < n; i++) {           s.insert(vec[i] & k);         }         if (s.size() != n)           cout << 2 << endl;         else           cout << -1 << endl;       }     }   }   