#include using namespace std; using int64 = long long; // const int mod = 1e9 + 7; const int mod = 998244353; const int64 infll = (1LL << 62) - 1; const int inf = (1 << 30) - 1; struct IoSetup { IoSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(10); cerr << fixed << setprecision(10); } } iosetup; template< typename T1, typename T2 > ostream &operator<<(ostream &os, const pair< T1, T2 > &p) { os << p.first << " " << p.second; return os; } template< typename T1, typename T2 > istream &operator>>(istream &is, pair< T1, T2 > &p) { is >> p.first >> p.second; return is; } template< typename T > ostream &operator<<(ostream &os, const vector< T > &v) { for(int i = 0; i < (int) v.size(); i++) { os << v[i] << (i + 1 != v.size() ? " " : ""); } return os; } template< typename T > istream &operator>>(istream &is, vector< T > &v) { for(T &in : v) is >> in; return is; } template< typename T1, typename T2 > inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); } template< typename T1, typename T2 > inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); } template< typename T = int64 > vector< T > make_v(size_t a) { return vector< T >(a); } template< typename T, typename... Ts > auto make_v(size_t a, Ts... ts) { return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...)); } template< typename T, typename V > typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) { t = v; } template< typename T, typename V > typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) { for(auto &e : t) fill_v(e, v); } template< typename F > struct FixPoint : F { FixPoint(F &&f) : F(forward< F >(f)) {} template< typename... Args > decltype(auto) operator()(Args &&... args) const { return F::operator()(*this, forward< Args >(args)...); } }; template< typename F > inline decltype(auto) MFP(F &&f) { return FixPoint< F >{forward< F >(f)}; } /** * @brief Binary-Trie * @docs docs/binary-trie.md */ template< typename T, int MAX_LOG, typename D = int > struct BinaryTrie { public: struct Node { Node *nxt[2]; vector< D > exist; D sum; vector< int > accept; Node() : nxt{nullptr, nullptr}, exist(MAX_LOG, 0), sum(0) {} }; Node *root; explicit BinaryTrie() : root(new Node()) {} explicit BinaryTrie(Node *root) : root(root) {} void add(const T &bit, int idx = -1, D delta = 1, T xor_val = 0) { root = add(root, bit, idx, MAX_LOG, delta, xor_val); } void erase(const T &bit, T xor_val = 0) { add(bit, -1, -1, xor_val); } Node *find(const T &bit, T xor_val = 0) { return find(root, bit, MAX_LOG, xor_val); } D count(const T &bit, T xor_val = 0) { auto node = find(bit, xor_val); return node ? node->exist : 0; } pair< T, Node * > min_element(T xor_val = 0) { assert(root->exist > 0); return kth_element(0, xor_val); } pair< T, Node * > max_element(T xor_val = 0) { assert(root->exist > 0); return kth_element(root->exist - 1, xor_val); } pair< T, Node * > kth_element(D k, T xor_val = 0) { // 0-indexed assert(0 <= k && k < root->exist); return kth_element(root, k, MAX_LOG, xor_val); } D count_less(const T &bit, T xor_val = 0) { // < bit return count_less(root, bit, MAX_LOG, xor_val); } private: virtual Node *clone(Node *t) { return t; } Node *add(Node *t, T bit, int idx, int depth, D x, T xor_val, bool need = true) { if(need) t = clone(t); if(depth == -1) { for(int k = 0; k <= MAX_LOG; k++) { t->exist[k] += (bit >> k) & 1; } t->sum++; if(idx >= 0) t->accept.emplace_back(idx); } else { bool f = (xor_val >> depth) & 1; auto &to = t->nxt[f ^ ((bit >> depth) & 1)]; if(!to) to = new Node(), need = false; to = add(to, bit, idx, depth - 1, x, xor_val, need); for(int k = 0; k <= MAX_LOG; k++) { t->exist[k] += (bit >> k) & 1; } t->sum++; } return t; } Node *find(Node *t, T bit, int depth, T xor_val) { if(depth == -1) { return t; } else { bool f = (xor_val >> depth) & 1; auto &to = t->nxt[f ^ ((bit >> depth) & 1)]; return to ? find(to, bit, depth - 1, xor_val) : nullptr; } } pair< T, Node * > kth_element(Node *t, D k, int bit_index, T xor_val) { // 0-indexed if(bit_index == -1) { return {0, t}; } else { bool f = (xor_val >> bit_index) & 1; if((t->nxt[f] ? t->nxt[f]->exist : 0) <= k) { auto ret = kth_element(t->nxt[f ^ 1], k - (t->nxt[f] ? t->nxt[f]->exist : 0), bit_index - 1, xor_val); ret.first |= T(1) << bit_index; return ret; } else { return kth_element(t->nxt[f], k, bit_index - 1, xor_val); } } } // ライブラリがバグっているのをやめてくれ! D count_less(Node *t, const T &bit, int bit_index, T xor_val) { if(bit_index == -1) return 0; D ret = 0; Node *l = t->nxt[0], *r = t->nxt[1]; if((xor_val >> bit_index) & 1) { swap(l, r); } bool f = (bit >> bit_index) & 1; if(f && l) { int all = l->sum; for(int k = 0; k <= MAX_LOG; k++) { int one = l->exist[k]; ret += 1LL * (1 << k) * one; int zero = all - one; if((xor_val >> k) & 1) { ret += 1LL * (1 << k) * zero; } } } t = f ? r : l; if(t) ret += count_less(t, bit, bit_index - 1, xor_val); return ret; } }; int main() { int N, X; cin >> N >> X; BinaryTrie< int64, 17 > trie; int64 ret = 0; for(int i = 0; i < N; i++) { int x; cin >> x; ret += trie.count_less(X, x); trie.add(x); } cout << ret << "\n"; }