#include<bits/stdc++.h> using namespace std; #define ll long long const ll N=1e5+10; ll n,k,a[N]; ll s; ll ans; ll cur; signed main(){ ans=0; scanf("%lld%lld",&n,&k); for(int i=1;i<=n;i++){ scanf("%lld",&a[i]); s+=a[i]; ans=max(ans,(a[i]^k)-a[i]); } ans+=s; printf("%lld",ans); //system("grep VmPeak/proc/$PPID/status"); return 0; }