#include <cassert>

#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
// #include <boost/foreach.hpp>
// #include <boost/range/algorithm.hpp>
#define rep(i,j,k) for(int i=(int)j;i<(int)k;i++)
#define ll long long
#define Sort(v) sort(all(v))
//#define INF 1e9
#define LINF (1LL<<40)
#define END return 0
#define pb push_back
#define se second
#define fi first
#define pb push_back
#define all(v) (v).begin() , (v).end()
#define MP make_pair
#define int long long
using namespace std;
int day[12]={31,28,31,30,31,30,31,31,30,31,30,31};
// int dx[]={0,1,0,-1};
// int dy[]={1,0,-1,0};
typedef pair<int,int> P;

const long long MOD=1000000007LL;
bool isupper(char c){if('A'<=c&&c<='Z')return 1;return 0;}
bool islower(char c){if('a'<=c&&c<='z')return 1;return 0;}
bool iskaibun(string s){for(int i=0;i<s.size()/2;i++)if(s[i]!=s[s.size()-i-1])return 0;return 1;}
bool isnumber(char c){return ('0'<=c&&c<='9');}
bool isalpha(char c){return (isupper(c)||islower(c));}
template<typename T> 
void print(vector<T> v){
    for(int i=0;i<v.size();i++){
        cout<<i<<": ";
        if(i)cout<<" ";
        cout<<v[i];
    }
    cout<<endl;
}
int INF=1e18;

template<typename T>
void printendl(vector<T> v){
    for(auto date:v)cout<<date<<endl;
}

template<typename T>
void printvv(vector<vector<T>> v){
    for(int i=0;i<v.size();i++){
        for(int j=0;j<v[i].size();j++){
            if(j)cout<<" ";
            cout<<v[i][j];
        }
        cout<<endl;
    }
}
int gcd(int a,int b){
    if(a<b)swap(a,b);
    if(b==0)return a;
    else return gcd(b,a%b);
}

struct Edge{
    int to,cost;
};


signed main (){
    int N,K;
    cin>>N>>K;
    vector<int> A(N);
    rep(i,0,N)cin>>A[i];
    int res=0;
    for(int i=60;i>=-1;i--){ // X_i < K_i、つまりX_i=0で、K_i=1であるようなiを全探索
        if(i!=-1 && !(K&(1LL<<i)))continue;
        int ans=0;
        for(int j=60;j>=0;j--){   //a[i]に対して、jビット目が立っているものを数える = ct
            int ct=0;
            rep(k,0,N){ 
                if(A[k]&(1LL<<j))ct++;
            }
            if(j>i){
                if(K&(1LL<<j))ans+=(1LL<<j)*(N-ct);
                else ans+=(1LL<<j)*ct;
            }else if(i==j){
                ans+=(1LL<<j)*ct;
            }else {
                ans+=(1LL<<j)*max(ct,N-ct);
            }
            // cout<<"N-ct"<<N-ct<<endl;
            // cout<<"K&(1<<j)"<<" "<<(K&(1LL<<j))<<endl;
        }
        res=max(res,ans);
    }
    cout<<res<<endl;

    
    // long long res = 0;
    // for (int d = 60; d >= -1; --d) { // d = -1 は X = K の場合
    //     if (d != -1 && !(K & (1LL<<d))) continue;
        
    //     long long tmp = 0;
    //     for (int e = 60; e >= 0; --e) {
    //         long long mask = 1LL<<e;
    //         int num = 0;
    //         for (int i = 0; i < N; ++i) if (A[i] & mask) ++num;
            
    //         if (e > d) {
    //             if (K & mask) tmp += mask * (N - num);
    //             else tmp += mask * num;
    //         }
    //         else if (e == d) {
    //             tmp += mask * num;
    //         }
    //         else {
    //             tmp += mask * max(num, N - num);
    //         }
    //         cout<<tmp<<endl;
    //     }
    //     res = max(res, tmp);
    // }
    // cout << res << endl;
    
}
/*
0001
0011
0110

0111

*/



Measured memory_bytes: 1024