#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
string i2s(int a) {
    string s = "";
    if (a == 0)
        s = "0";
    else {
        while (a > 0) {
            s += (a%2 + '0');
            a /= 2;
        }
    }
    reverse(s.begin(),s.end());
    return s;
}
int s2i(string s) {
    int mn = 1;
    int brojac = 0;
    for (int i = s.size() - 1; i >= 0; i--) {
        brojac += mn*(s[i] -'0');
        mn *= 2;
    }
    return brojac;
}
int main() {
    int n,k;
    cin >> n >> k;
    int mat[31][n+1];
    for (int i = 0; i < 31; i++)
        for (int j = 0; j < n; j++)
            mat[i][j] = 0;

    for (int i = 0; i < n; i++) {
        int a;
        cin >> a;
        string s = i2s(a);
        int br = s.size() - 1;
        for (int j = 30; j >= 0; j--) {
            mat[j][i] = (s[br] - '0');
            br--;
            if (br == -1)
                break;
        }
    }
    vector<int> vis(n+1, 0);
    string  kr = "";
    for (int i = 0; i < 31; i++) {
        int bro = 0;
        for (int j = 0; j < n; j++) {
            if (!vis[j]) {
                bro += mat[i][j];
            }
        }
        if (bro < k) {
            kr += '0';
            continue;
        }
        else {
            kr += '1';
            for (int j = 0; j < n; j++) {
                if (!vis[j] && mat[i][j] == 0)
                    vis[j] = true;
            }
        }

    }
    cout<<s2i(kr)<<endl;
    return 0;
}
 /*

#include <iostream>
#include <string>
#include <vector>
using namespace std;
typedef long long ll;
vector<int> low;
vector<int> dfs_num;
vector<int> parent;
int N, M;
vector<int> graf[int(1e5)+10];
vector<bool> articulation_map;
vector<int> ap;
vector<pair<int,int>> bridges;
void articulation_points(int u){
    static int dfs_num_cnt = 0;
    low[u] = dfs_num[u] = ++dfs_num_cnt;
    int children = 0;
    for(int i=0;i<graf[u].size();i++) {
        int v = graf[u][i];
        if (dfs_num[v] == -1) {
            parent[v] = u;
            children++;
            articulation_points(v);
            low[u] = min(low[u], low[v]);
            if (parent[u] == -1 && children > 1) {
                articulation_map[u] = true;
            } else if (parent[u] != -1 && low[v] >= dfs_num[u]) {
                articulation_map[u] = true;
            }
            if (low[v] > dfs_num[u]) {
                bridges.push_back({u, v});
            }
        } else if (v != parent[u]) {
            low[u] = min(low[u], dfs_num[v]);
        }
    }
}
void bridg_find(){
    cout << M;
    for(int i=0;i<M;i++){
        int a, b;
        a--,b--;
        cin >> a >> b;
        graf[a].push_back(b);
        graf[b].push_back(a);
    }
    low.assign(N,-1);
    dfs_num.assign(N,-1);
    parent.assign(N, -1);
    articulation_map.assign(N, false);
    for(int i = 0;i<N;i++){
        if(dfs_num[i] == -1){
            articulation_points(i);
        }
    }
    for(int i=0;i<N;i++){
        if(articulation_map[i]){
            ap.push_back(i);
            cout << i;
        }
    }
}

int main() {
    cin >> N >> M;
    bridg_find();
    int Q;
    cin >> Q;
    int
    for(int i=0;i<Q;i++){
        int c;
        cin >> c;
        int sum = 0;
        for(int i=0;i<c;i++){
            int j;
            cin >> j;
            sum += articulation_map[j];
        }
        cout <<
    }
    return 0;
}
*/