/******************
*  Author: BD747  *
******************/
/*


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*/
#include<algorithm>
#include<cstdio>
#include<iostream>
#include<cstring>
#include<cmath>
#include<map>
#include<queue>
#include<set>
#include<sstream>
#include<stack>
#include<string>
#include<vector>
#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

ll a[100005];
ll n,k;

int main(){
    
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin>>n>>k;
    for(int i=0;i<n;i++){
        cin>>a[i];
    }
    ll p=0;
    ll ans=0;
    while((1LL<<p)<=k){
        ll cnt=0;
        for(int i=0;i<n;i++){
            cnt+=!(a[i]&(1LL<<p));
        }
        if(cnt>n/2) ans|=(1LL<<p);
        p++;
    }
    while(ans>k){
        if(((1LL<<p)&k)<((1LL<<p)&ans)) ans&=~(1LL<<p);
        p--;
    }
    ll res=0;
    for(int i=0;i<n;i++){
        res+=ans^a[i];
    }
    cout<<res<<endl;
    return 0;
}

Measured memory_bytes: 1024