#include <iostream>
#include <fstream>
#include <iomanip>
#include <climits>
#include <limits>
#include <algorithm>
#include <array>
#include <vector>
#include <deque>
#include <queue>
#include <list>
#include <stack>
#include <string>
#include <functional>
#include <numeric>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <unordered_map>
#include <random>
#include <cmath>
#include <complex>
// #include "utiltime.hpp"

using namespace std;

typedef long long int ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef pair<int, int> P;
typedef pair<ll, ll> Pll;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef complex<double> cdouble;

const int INFL = (int)1e9;
const ll INFLL = (ll)1e18;
const double INFD = numeric_limits<double>::infinity();
const double PI = 3.14159265358979323846;
#define Loop(i, n) for(int i = 0; i < (int)(n); i++)
#define Loopll(i, n) for(ll i = 0; i < (ll)(n); i++)
#define Loop1(i, n) for(int i = 1; i <= (int)(n); i++)
#define Loopll1(i, n) for(ll i = 1; i <= (ll)(n); i++)
#define Loopr(i, n) for(int i = (int)(n) - 1; i >= 0; i--)
#define Looprll(i, n) for(ll i = (ll)(n) - 1; i >= 0; i--)
#define Loopr1(i, n) for(int i = (int)(n); i >= 1; i--)
#define Looprll1(i, n) for(ll i = (ll)(n); i >= 1; i--)
#define Foreach(buf, container) for(auto buf : container)
#define Loopdiag(i, j, h, w, sum) for(int i = ((sum) >= (h) ? (h) - 1 : (sum)), j = (sum) - i; i >= 0 && j < (w); i--, j++)
#define Loopdiagr(i, j, h, w, sum) for(int j = ((sum) >= (w) ? (w) - 1 : (sum)), i = (sum) - j; j >= 0 && i < (h); j--, i++)
#define Loopdiagsym(i, j, h, w, gap) for (int i = ((gap) >= 0 ? (gap) : 0), j = i - (gap); i < (h) && j < (w); i++, j++)
#define Loopdiagsymr(i, j, h, w, gap) for (int i = ((gap) > (h) - (w) - 1 ? (h) - 1 : (w) - 1 + (gap)), j = i - (gap); i >= 0 && j >= 0; i--, j--)
#define Loopitr(itr, container) for(auto itr = container.begin(); itr != container.end(); itr++)
#define Sort(container) sort(container.begin(), container.end())
#define Reverse(container) reverse(container.begin(), container.end())
#define printv(vector) Loop(extra_i, vector.size()) { cout << vector[extra_i] << " "; } cout << endl;
#define printmx(matrix) Loop(extra_i, matrix.size()) { Loop(extra_j, matrix[extra_i].size()) { cout << matrix[extra_i][extra_j] << " "; } cout << endl; }
#define quickio() ios::sync_with_stdio(false); cin.tie(0);
#define readfile(filename) ifstream in(filename); cin.rdbuf(in.rdbuf());
#define bitmanip(m,val) static_cast<bitset<(int)m>>(val)
#define Comp(type_t) bool operator<(const type_t &another) const
#define fst first
#define snd second
bool nearlyeq(double x, double y) { return abs(x - y) < 1e-9; }
bool inrange(int x, int t) { return x >= 0 && x < t; }
ll rndf(double x) { return (ll)(x + (x >= 0 ? 0.5 : -0.5)); }
ll floorsqrt(double x) { ll m = (ll)sqrt(x); return m + (m * m <= (ll)(x) ? 0 : -1); }
ll ceilsqrt(double x) { ll m = (ll)sqrt(x); return m + ((ll)x <= m * m ? 0 : 1); }
ll rnddiv(ll a, ll b) { return (a / b + (a % b * 2 >= b ? 1 : 0)); }
ll ceildiv(ll a, ll b) { return (a / b + (a % b == 0 ? 0 : 1)); }
ll gcd(ll m, ll n) { if (n == 0) return m; else return gcd(n, m % n); }
ll lcm(ll m, ll n) { return m * n / gcd(m, n); }

/*******************************************************/

vi trans(ll x) {
	vi ret;
	while (x > 0) {
		ret.push_back(x & 1);
		x >>= 1;
	}
	while (ret.size() < 60) ret.push_back(0);
	return ret;
}

int main() {
	int n; cin >> n;
	ll k; cin >> k;
	vvi a(n);
	Loop(i, n) {
		ll x; cin >> x;
		a[i] = trans(x);
	}
	ll ans = 0;
	vi d = trans(k);
	vvll dp(2, vll(60, 0));
	bool limit = true;
	Loopr(j, 59) {
		ll cnt = 0;
		Loop(i, n) {
			cnt += a[i][j];
		}
		ll x0 = cnt;
		ll x1 = n - cnt;
		if (d[j] == 1) {
			dp[0][j] = max(dp[0][j], dp[0][j + 1] + (x1 << j));
			dp[1][j] = max(dp[1][j], dp[0][j + 1] + (x0 << j));
			dp[1][j] = max(dp[1][j], dp[1][j + 1] + (x0 << j));
			if (!limit) dp[1][j] = max(dp[1][j], dp[1][j + 1] + (x1 << j));
			limit = false;
		}
		else {
			dp[0][j] = max(dp[0][j], dp[0][j + 1] + (x0 << j));
			dp[1][j] = max(dp[1][j], dp[1][j + 1] + (x0 << j));
			if (!limit) dp[1][j] = max(dp[1][j], dp[1][j + 1] + (x1 << j));
		}
	}
	cout << max(dp[0][0], dp[1][0]) << endl;
}

Measured memory_bytes: 29184