#include <iostream>
#include <string>
#include <vector>
#include <set>
#include <stack>
#include <queue>
#include <map>
#include <algorithm>
#include <iomanip>
#include <math.h>
#include <string.h>
#include <cstdio>
#include <tuple>
using namespace std; using ll = long long; using ld = long double;  using pll = pair<ll, ll>;
using vl = vector<ll>; using vll = vector<vl>; using vpll = vector<pll>;
const ld PI = 3.1415926535897932;
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define rep1(n) for(ll i=0;i<n;++i)
#define rep2(i,n) for(ll i=0;i<n;++i)
#define rep3(i,a,b) for(ll i=a;i<b;++i)
#define rep4(i,a,b,c) for(ll i=a;i<b;i+=c)
#define rep(...) overload4(__VA_ARGS__,rep4,rep3,rep2,rep1)(__VA_ARGS__)
#define mp make_pair
#define mt make_tuple
#define INT(...) int __VA_ARGS__;in(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;in(__VA_ARGS__)
#define ULL(...) ull __VA_ARGS__;in(__VA_ARGS__)
#define STR(...) string __VA_ARGS__;in(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__;in(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__;in(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__;in(__VA_ARGS__)
void in() {}
void debug_out() { cerr << endl; }
template<typename Head, typename... Tail>
void debug_out(Head h, Tail... t) {
	cerr << " " << h;
	if (sizeof...(t) > 0) cerr << " :";
	debug_out(t...);
}
template <typename T>
ostream& operator<<(ostream& os, vector<T> vec) {
	for (size_t i = 0; i < vec.size(); i++)os << vec[i] << (i + 1 == vec.size() ? "" : " ");
	return os;
}
ll ctoi(char c) {
	switch (c) {
	case '0': return 0; case '1': return 1; case '2': return 2;
	case '3': return 3; case '4': return 4; case '5': return 5;
	case '6': return 6; case '7': return 7; case '8': return 8;
	case '9': return 9;  default: return 0;
	}
}
bool pairCompare(const pll firstElof, pll secondElof)
{
	return firstElof.first > secondElof.first;
}
//**Snippetリスト**//
//rep, vin, all, iteLoop//
//bitSearch, bitList, nod, gcdlcm, isPrime, primeFactorize, Npow, divisor, modinv, dfs, bfs, eratos//
//dijkstra, WarshallFloyd, BellmanFord, UnionFind, COM, digitDP ,RMQ//
ll i, j, k, l; ll N, M, K, H, W, L, X, Y, Z, R;
ll MOD = 1000000007; ll INF = 1LL << 62; ll ans = 0; ll z = 0, o = 1;
vl flag, color, D; vll path;
vl bitList(ll n, ll k, ll f) {
	vl bitList(k);
	for (ll i = 0; i < k; i++) {
		bitList[i] = f % n; f /= n;
	}
	return bitList;
}
int main() {
	cin >> N >> K; vl one(48);
	for (j = 0; j < 48; j++) one[j] = 0;
	for (i = 0; i < N; i++) {
		ll a; cin >> a; vl B = bitList(2, 48, a);
		for (j = 0; j < 48; j++) one[j]+=B[j];
	}
	vl P = bitList(2, 48, K); vll dp(49, vl(2, 0));
	reverse(P.begin(), P.end()); reverse(one.begin(), one.end());
	for (i = 0; i < 49; i++) for (j = 0; j < 2; j++) dp[i][j] = -1;
	dp[0][0] = 0;
	for (i = 0; i < 48; i++) {
		for (ll smaller = 0; smaller < 2; smaller++) {
			if (dp[i][smaller] == -1) continue;
			ll X = pow(2, 47 - i);
			dp[i + 1][smaller || P[i]] = max(dp[i + 1][smaller || P[i]], dp[i][smaller] + X * one[i]);
			if (smaller) dp[i + 1][1] = max(dp[i + 1][1], dp[i][smaller] + X * (N - one[i]));
			else if (P[i]) dp[i + 1][0] = max(dp[i + 1][0], dp[i][smaller] + X * (N - one[i]));
		}
	}
	cout << max(dp[48][0], dp[48][1]);
}

Measured memory_bytes: 512