#include <iostream>
using namespace std;

const int MAX_N = 100005;
long long A[MAX_N];

int main() {
    int N;
    long long K;
    cin >> N >> K;

    for (int i = 0; i < N; ++i) {
        cin >> A[i];
    }

    long long bitCount[45] = {0};

    for (int i = 0; i < N; ++i) {
        for (int b = 0; b < 45; ++b) {
            if ((A[i] >> b) & 1) {
                bitCount[b]++;
            }
        }
    }

    long long bestX = 0;
    for (int b = 44; b >= 0; --b) {
        long long tempX = bestX | (1LL << b);
        if (tempX > K) continue;

        long long ones = bitCount[b];
        long long zeros = N - ones;

        if (zeros > ones) {
            bestX = tempX;
        }
    }

    long long result = 0;
    for (int i = 0; i < N; ++i) {
        result += (A[i] ^ bestX);
    }

    cout << result << endl;
    return 0;
}