#include <bits/stdc++.h>
using namespace std;
// define
#define int long long
#define UNIQUE(v) v.erase(unique(all(v)), v.end());
#define ZIP(v) sort(all(v)),UNIQUE(v)
#define ADD(a, b) a = (a + b) % mod
#define SUB(a, b) a = (a+mod-b)%mod
#define MUL(a, b) a = (a * b) % mod
#define rollcall cout << "I'm Sucu." << endl;
#define repi(i,m,n) for(int i = m;i < n;i++)
#define drep(i,n,m) for(int i = n;i >= m;i--)
#define rep(i,n) repi(i,0,n)
#define rrep(i,n) repi(i,1,n+1)
#define chmin(x,y) x = min(x,y)
#define chmax(x,y) x = max(x,y)
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(), v.rend()
#define dmp(x,y) make_pair(x,y)
#define pb(x) push_back(x)
#define pf(x) push_front(x)
#define fi first
#define se second
// debug
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p){
  os << "(" << p.first << "," << p.second << ")";return os;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v){
  for (auto it = v.begin();it != v.end();++it){
    if(it != v.begin())os << " ";os << *it;
      }return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &mp){
  for(auto x: mp)os << "(" << x.first << "," << x.second << ")" << endl;
  return os;
}
template<typename T, int SIZE>
int array_length(const T (&)[SIZE]){return SIZE;}
template<typename T, int N>
void PRINTF(const T (&a)[N], int s = N, int t = -1, bool f = true){
	if(t == -1){rep(i,s){if(i)cout << " ";cout << a[i];}}
	else repi(i,s,t){if(i!=s)cout << " ";cout << a[i];}
	if(f)cout << "\n";
}
template<typename T, int N1, int N2>
void PRINTF(const T (&a)[N1][N2], int h = N1, int w = N2){
	rep(i,h){rep(j,w){cout << a[i][j] << " \n"[j==w-1];}}
}
string substr(const string &str, int S1, int S2 = -1){
  if(S2 == -1)return str.substr(S1);
  return str.substr(S1, S2-S1);
}
// typedef
typedef complex<double> Point;
typedef pair<int, int> P;
typedef pair<int, P> PP;
typedef pair<P, int> Pi;
typedef vector<int> vi;
typedef deque<int> dq;
const int inf = 1e9+7;
const int INF = 1e18+7;

int a[200000], fac[50], cnt[50], num[50], dp[50][2];
string to_binary(int n){
  string str = "";
  vector<int> v;
  while(n){
    v.pb(n%2);
    n /= 2;
  }
  if(v.size() == 0)return "0";
  drep(i,v.size()-1,0)str.pb(v[i]+'0');
  return str;
}
void init(int d){
  fac[d-1] = 1;
  drep(i,d-1,1)fac[i-1] = fac[i]*2;
}
int calc(int n, int d){
  int ans = 0, tmp = 1;
  drep(i,d-1,0){
    cnt[i] += n%2;
    n = n/2;
    tmp *= 2;
  }
  return n*tmp;
}

signed main(){
  int n, k;
  scanf("%lld%lld", &n, &k);
  rep(i,n)scanf("%lld", &a[i]);
  string str = to_binary(k);
  int d = str.size();
  int ans = 0;
  init(d);
  rep(i,n)ans += calc(a[i], d);
  rep(i,d){
    if(i == 0){
      dp[0][0] = cnt[0]*fac[0];
      if(str[i] == '1')dp[0][1] = (n-cnt[0])*fac[0];
      continue;
    }
    if(str[i] == '0'){
      dp[i][0] = dp[i-1][0]+max(cnt[i], n-cnt[i])*fac[i];
      dp[i][1] = dp[i-1][1]+cnt[i]*fac[i];
    }else{
      dp[i][1] = dp[i-1][1]+(n-cnt[i])*fac[i];
      dp[i][0] = dp[i-1][1]+cnt[i]*fac[i];
      chmax(dp[i][0], dp[i-1][0]+max(cnt[i], n-cnt[i])*fac[i]);
    }
  }
  // rep(i,d)printf("%lld ", cnt[i]);printf("\n");
  printf("%lld\n", ans+max(dp[d-1][0], dp[d-1][1]));
  return 0;
}






Measured memory_bytes: 1024