#include #include #include #include #include #include #include template inline bool chmin(T &lhs, const U &rhs) { if (lhs > rhs) { lhs = rhs; return true; } return false; } template inline bool chmax(T &lhs, const U &rhs) { if (lhs < rhs) { lhs = rhs; return true; } return false; } struct range { using itr = int64_t; struct iterator { itr i; constexpr iterator(itr i_): i(i_) { } constexpr void operator ++ () { ++i; } constexpr itr operator * () const { return i; } constexpr bool operator != (iterator x) const { return i != x.i; } }; const iterator l, r; constexpr range(itr l_, itr r_): l(l_), r(std::max(l_, r_)) { } constexpr iterator begin() const { return l; } constexpr iterator end() const { return r; } }; struct revrange { using itr = int64_t; struct iterator { itr i; constexpr iterator(itr i_): i(i_) { } constexpr void operator ++ () { --i; } constexpr itr operator * () const { return i; } constexpr bool operator != (iterator x) const { return i != x.i; } }; const iterator l, r; constexpr revrange(itr l_, itr r_): l(l_ - 1), r(std::max(l_, r_) - 1) { } constexpr iterator begin() const { return r; } constexpr iterator end() const { return l; } }; using i32 = int32_t; using i64 = int64_t; using u32 = uint32_t; using u64 = uint64_t; constexpr i32 inf32 = (i32(1) << 30) - 1; constexpr i64 inf64 = (i64(1) << 62) - 1; int main() { size_t N; u32 X; std::cin >> N >> X; std::map map; std::vector A(N); for (auto &x: A) { std::cin >> x; map[x]++; } u64 ans = 0; for (auto x: A) { auto itr = map.find(x ^ X); if (itr != map.end()) { ans += itr -> second; if ((x ^ x) == X) { --ans; } } } std::cout << ans / 2 << '\n'; return 0; }