#include<iostream> using namespace std; long long n,k; int main(){ cin>>n>>k; long long a[n]; long long maxx=0,ans=0; for(long long i=1;i<=n;i++){ cin>>a[i]; ans+=a[i]; } for(long long i=1;i<=n;i++){ //cout<<i<<" "<<maxx<<" "<<(a[i]^k)<<endl; maxx=max(maxx,ans-a[i]+(a[i]^k)); } cout<<max(maxx,ans)<<endl; return 0; }