#include<bits/stdc++.h> #define int long long using namespace std; int a[200010]; signed main(){ freopen("xor.in","r",stdin); freopen("xor.out","w",stdout); int n,k; cin>>n>>k; int sum=0; for(int i=1;i<=n;i++){ cin>>a[i]; sum+=a[i]; } int ans=0; for(int i=1;i<=n;i++){ ans=max(ans,sum-a[i]+(a[i]^k)); } cout<<ans; return 0; }