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