#include <iostream>
#include <vector>
#include<list>
#include <algorithm>
#include <string>
#include <math.h>
#include<map>
#include <utility>
#include<set>

#include<queue>
using namespace std;
#define REP(i,k,n) for(int i=k;i<n;i++)
 
#define INF 1844674407370955161
typedef long long unsigned int ll;
#define SIZE_OF_ARRAY(array) (sizeof(array)/sizeof(array[0]))
#define MOD 1000000007

template<typename T>
int vector_finder(std::vector<T> vec, T number) {
  auto itr = std::find(vec.begin(), vec.end(), number);
  size_t index = std::distance( vec.begin(), itr );
  if (index != vec.size()) { // 発見できたとき
    return 1;
  }
  else { // 発見できなかったとき
    return 0;
  }
}

template<typename T>
T gcd(T a,T b){
	if(b>0){
		return gcd(b, a % b);
	}else{
		return a;
	}
}

template<typename T>
T lcm(T a,T b){
	T g = gcd(a, b);
	return a * b / g;
}

void clear( std::queue<pair<int,int> > &q )
{
   std::queue<pair<int,int> > empty;
   std::swap( q, empty );
}
bool IsPrime(int num)
{
    if (num < 2) return false;
    else if (num == 2) return true;
    else if (num % 2 == 0) return false; // 偶数はあらかじめ除く

    double sqrtNum = sqrt(num);
    for (int i = 3; i <= sqrtNum; i += 2)
    {
        if (num % i == 0)
        {
            // 素数ではない
            return false;
        }
    }

    // 素数である
    return true;
}
template<typename T>
std::vector<T> enum_div(T n)//nの約数を列挙
{
	std::vector<T> ret;
	for(T i=1 ; i*i<=n ; ++i)
	{
		if(n%i == 0)
		{
			ret.push_back(i);
			if(i!=1 && i*i!=n)
			{
				ret.push_back(n/i);
			}
		}
	}
	return ret;
}

map< int, int > prime_factor(int n) {
  map< int, int > ret;
  for(int i = 2; i * i <= n; i++) {
    while(n % i == 0) {
      ret[i]++;
      n /= i;
    }
  }
  if(n != 1) ret[n] = 1;
  return ret;
}
class DisjointSet{
    public:
        vector<int> rank, p;

        DisjointSet(){
        }

        DisjointSet(int size){
            rank.resize(size, 0);
            p.resize(size, 0);
            for (int i = 0; i < size;i++){
                makeSet(i);
            }
        }
        void makeSet(int x){
            p[x] = x;
            rank[x] = 0;
        }

        bool same(int x,int y){
            return findSet(x) == findSet(y);
        }
        void unite(int x,int y){
            link(findSet(x), findSet(y));
        }
        void link(int x,int y){
            if(rank[x]>rank[y]){
                p[y] = x;
            }else{
                p[x] = y;
                if(rank[x]==rank[y]){
                    rank[y]++;
                }
            }
        }
        int findSet(int x){
            if(x!=p[x]){
                p[x] = findSet(p[x]);
            }
            return p[x];
        }
};


int main()
{
  int N;
  ll K;

  cin >> N >> K;
  
  ll A[N];
  ll B[N];
  REP(i, 0, N)
  {
    cin >> A[i];
    B[i] = A[i];
  }
  int s[45];
  int x[45];
  int ck[45];
  REP(i, 0, 45)
  {
    ll d = K % 2;
    K /= 2;
    s[44 - i] = d;
    ck[44-i] = 0;
    REP(j, 0, N)
    {
      ll d = A[j] % 2;
      A[j] /= 2;
      ck[44 - i] += d;
    }
  }
  
  
  int flag = false;
  REP(i, 0, 45)
  {
    int f = s[i];
    
    if(f==0&&!flag){
      x[i] = 0;
    }else if(!flag&&f==1){
      if(ck[i]>N-ck[i]){
        x[i] = 0;
        flag = true;
      }else{
        x[i] = 1;
        
      }
    }else if(flag){
      if(ck[i]>N-ck[i]){
        x[i] = 0;
      }else{
        x[i] = 1;
      }
    }
  }
  ll xans = 0;
  ll po = 1;
  REP(i,0,45){
    xans += x[44 - i] * po;
    po *= 2;
  }

  ll ans = 0;
  REP(i,0,N){
    ans += xans^B[i];
  }
  cout << ans << endl;
}

Measured memory_bytes: 1792