//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<n; ++i)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
using namespace std;
using ll = int64_t;
using ld = long double;
using P = pair<int, ll>;
using vs = vector<string>;
using vi = vector<int>;
using vvi = vector<vi>;
template<class T> using PQ = priority_queue<T>;
template<class T> using PQG = priority_queue<T, vector<T>, greater<T> >;
const int INF = 0xccccccc;
const ll LINF = 0xcccccccccccccccLL;
template<typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {return a < b && (a = b, true);}
template<typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {return a > b && (a = b, true);}
template<typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) { return is >> p.first >> p.second;}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << p.first << ' ' << p.second;}

#pragma GCC target ("sse4")

//head



int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, t;
	cin >> n >> t;
	vi a(n);
	rep(i, n) cin >> a[i];
	vector<P> pre(31, P(-1, 0)), now(31);
	pre[__builtin_popcount(t)] = P(t, 0);
	rep(i, n) {
		fill(now.begin(), now.end(), P(-1, 0));
		rep(j, 31) {
			auto [x, u] = pre[j];
			if(x == -1) continue;
			int t = x&a[i];
			chmax(now[__builtin_popcount(t)], P(t, u+abs(x-t)));
			t = x|a[i];
			chmax(now[__builtin_popcount(t)], P(t, u+abs(x-t)));
		}
		now.swap(pre);
	}
    ll z = 0;
	rep(i, 31) if(pre[i].first != -1) {
		chmax(z, pre[i].second);
	}
	cout << z << endl;
}