#include<bits/stdc++.h>

#define debug(x) cerr << #x << ": " << x << endl
#define debugArray(x,n) for(long long hoge = 0; (hoge) < (n); ++ (hoge)) cerr << #x << "[" << hoge << "]: " << x[hoge] << endl
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef vector<ll> vll;
const ll INF = LLONG_MAX/2;
const ll MOD = 1e9+7;
const double EPS=1e-12;

template<typename KEYTYPE = unsigned long long, int B = 64>
class BinaryTrie {
    struct node {
        int cnt;
        KEYTYPE lazy;
        node *ch[2];
        node() : cnt(0), lazy(0), ch{ nullptr, nullptr } {}
    };
    node* insert_node(node* t, KEYTYPE key, int b = B - 1) {
        if (!t) t = new node;
        t->cnt += 1;
        if (b < 0) return t;
        push(t, b);
        bool f = (key >> (KEYTYPE)b) & (KEYTYPE)1;
        t->ch[f] = insert_node(t->ch[f], key, b - 1);
        return t;
    }
    node* erase_node(node* t, KEYTYPE key, int b = B - 1) {
        assert(t);
        t->cnt -= 1;
        if (t->cnt == 0) return nullptr;
        if (b < 0) return t;
        push(t, b);
        bool f = (key >> (KEYTYPE)b) & (KEYTYPE)1;
        t->ch[f] = erase_node(t->ch[f], key, b - 1);
        return t;
    }
    //[
    void push(node* t, int b) {
        if ((t->lazy >> (KEYTYPE)b) & (KEYTYPE)1) swap(t->ch[0], t->ch[1]);
        if (t->ch[0]) t->ch[0]->lazy ^= t->lazy;
        if (t->ch[1]) t->ch[1]->lazy ^= t->lazy;
        t->lazy = 0;
    }
    KEYTYPE get(node* t, int k, int b = B - 1) {
        if (b < 0) return 0;
        push(t, b);
        int m = t->ch[0] ? t->ch[0]->cnt : 0;
        return k < m ? get(t->ch[0], k, b - 1) : get(t->ch[1], k - m, b - 1) | ((KEYTYPE)1 << (KEYTYPE)b);
    }
    //]
    node *root;
public:
    BinaryTrie() : root(nullptr) {}
    void insert(KEYTYPE key) {
        root = insert_node(root, key);
    }
    void erase(KEYTYPE key) {
        root = erase_node(root, key);
    }
    //[
    int size() const {
        return root ? root->cnt : 0;
    }
    KEYTYPE kth_element(int k) {
        assert(0 <= k && k < size());
        return get(root, k);
    }
    //]
};

signed main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll Q,K;cin>>Q>>K;K--;
  BinaryTrie<> S;
  for(ll q=0;q<Q;q++){
    ll op;cin>>op;
    if(op&1){
      ll v;cin>>v;
      S.insert(v);
    }else{
      ll ans=-1;
      if(S.size()>K){
        ans = S.kth_element(K);
        S.erase(ans);
      }
      cout<<ans<<endl;
    }
  }
  return 0;
}