#include<bits/stdc++.h> using namespace std; #define int long long const int N=1e5+10; int n,k,mmax=-0x7f,sum,a[N]; signed main(){ //freopen("xor.in","r",stdin); //freopen("xor.out","w",stdout); cin>>n>>k; for(int i=1;i<=n;i++){cin>>a[i];sum+=a[i];} for(int i=1;i<=n;i++){ int p=a[i]^k; mmax=max(mmax,p-a[i]); } //cout<<sum<<" "<<mmax<<endl; cout<<sum+mmax<<endl; fclose(stdin); fclose(stdout); return 0; }