//
//
//  Codeforces: ganariya
//  AtCoder: ganariya2525
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//  MMMMMMMMMMMMMMNyrrrRrWMMmzOrzdNyrrrZNvrwQWWfb....(r~~_J>_.....~.~~-dpfpffpfpppWHHMNdMMMMMMMMMMMMMMMM
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//  MMMMMMMMMMMMMMMMNOtXtdMMMMMNxzZMMNmgHyVVVVVW%..?/(.,(x-..........(HfffpffpffpffWHHffpffppfVyyWMMMMMM


//include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <unordered_map>
#include <climits>
#include <set>
#include <unordered_set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <queue>
#include <random>
#include <complex>
#include <regex>
#include <locale>
#include <random>
#include <type_traits>

using namespace std;

#define SHOW_VECTOR(v) {std::cerr << #v << "\t:";for(const auto& xxx : v){std::cerr << xxx << " ";}std::cerr << "\n";}
#define SHOW_MAP(v){std::cerr << #v << endl; for(const auto& xxx: v){std::cerr << xxx.first << " " << xxx.second << "\n";}}

using LL = long long;

//~~~~~~~~~~~~~~~~~~~~~_(＾～＾ ｣ ∠)_~~~~~~~~~~~~~~~~~~~~~

int main() {

    LL N, K;
    cin >> N >> K;

    vector<LL> A(N), B(N);
    for (int i = 0; i < N; i++) cin >> A[i] >> B[i];

    LL ans = 0;
    for (int i = 0; i < N; i++) {
        bool good = true;
        for (LL j = 0; j <= 40; j++) {
            if (A[i] & (1LL << j) && !(K & (1LL << j))) {
                good = false;
            }
        }
        if (good) ans += B[i];
    }

 //   cout << ans;

    for (LL i = 40; i >= 0; i--) {
        if (K & (1LL << i)) {
            LL sum = 0;
            LL T = K;
            T ^= (1LL << i);
            for (LL j = 0; j < i; j++) T |= (1LL << j);
            for (LL j = 0; j < N; j++) {
                bool good = true;
                for (LL k = 0; k <= 40; k++) {
                    if (A[j] & (1LL << k) && !(T & (1LL << k))) {
                        good = false;
                    }
                }
                if (good) sum += B[j];
            }
            ans = max(ans, sum);
        }
    }

    cout << ans << endl;

    return 0;
}






































Measured memory_bytes: 1920