//#include #include //#include using namespace std; //using namespace atcoder; typedef long long ll; typedef unsigned int uint; typedef unsigned long long ull; typedef pair p; const int INF = 1e9; const ll LINF = ll(1e18); const int MOD = 1000000007; const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0}; const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1}, Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1}; #define yes cout << "Yes" << endl #define YES cout << "YES" << endl #define no cout << "No" << endl #define NO cout << "NO" << endl #define rep(i, n) for (int i = 0; i < n; i++) #define FOR(i, m, n) for (int i = m; i < n; i++) #define ALL(v) v.begin(), v.end() #define debug(v) \ cout << #v << ":"; \ for (auto x : v) \ { \ cout << x << ' '; \ } \ cout << endl; template bool chmax(T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; } template bool chmin(T &a, const T &b) { if (b < a) { a = b; return 1; } return 0; } //cout<>n>>x; vector a(n); map m; rep(i,n){ cin>>a[i]; m[a[i]]++; } ll ans=0; rep(i,n){ ans+=m[a[i]^x]; } ans/=2; cout<