#pragma GCC optimize("Ofast") #include #include #include using namespace std; using namespace __gnu_pbds; using ll = long long; using u64 = uint_fast64_t; using pii = pair; using pll = pair; #define rep(i, n) for(int i = 0; i < (n); ++i) #define all(x) (x).begin(),(x).end() constexpr char ln = '\n'; constexpr long long MOD = 1000000007; //constexpr long long MOD = 998244353; template inline bool chmax(T1 &a, T2 b) { if (a < b) { a = b; return true;} return false; } template inline bool chmin(T1 &a, T2 b) { if (a > b) { a = b; return true;} return false; } inline int popcount(int x) {return __builtin_popcount(x);} inline int popcount(long long x) {return __builtin_popcountll(x);} void print() { cout << "\n"; } template void print(const T &x, const Args &... args) { cout << x << " "; print(args...); } /////////////////////////////////////////////////////////////////////////////////////////////////////////////// int main() { ios::sync_with_stdio(false); cin.tie(nullptr); ll N,X; cin >> N >> X; ll ans = 0; map dic; rep(i,N) { ll a; cin >> a; ll val = X^a; if (dic.count(val)) ans += dic[val]; dic[a]++; } cout << ans << ln; }