#include #pragma optimize ("O3") //#pragma target ("sse4") const int MAXN=200017; using namespace std; #define endl '\n' int a[MAXN]; int k, n; map m; long long ans=0; void mainp() { freopen ("xor.in","r",stdin); freopen ("xor.out","w",stdout); cin>>n>>k; for(int i=0; i>a[i]; int need=a[i]^k; ans+=m[need]; m[a[i]]++; } cout<