#include<bits/stdc++.h>
using namespace std;

#define ll unsigned long long
#define endl '\n'
const int N = 1e6+4;

void solve(int cs){
    int n;cin>>n;
    ll k;cin>>k;
    std::vector<ll>v ;
    
    int bit[50] = {0};
    for(int i = 0; i < n; i++){
        ll a;cin>>a;
        v.push_back(a);
        for(int j = 0; j < 46; j++){
            if((a&(1ll<<j)))bit[j]++;
        }
    }
    //cout<<(3&4) <<" "<<(1&4) <<" "<<(6&4)<<endl;
    //cout<<bit[2]<<endl;
    ll ans = 0;
    ll tm = 0;
    for(int i = 45; i>=0; i--){
        int unset = n-bit[i];
        
        if(bit[i] < unset){
            if((tm|(1ll<<i)) <= k){
                tm |= (1ll<<i);
            }
        }
    }
    if(tm == 0)tm = 1;
    for(auto u:v){
        ans += (u^tm);
    }
    cout<<ans<<endl;
}
   
int main()
{

    ios_base::sync_with_stdio(false);cin.tie(0);
    int t=1,cs=0;
    //cin >> t;
    while(t--)
    {
        solve(++cs);
    }

    return 0;
}