#include<bits/stdc++.h>
using namespace std;int64_t K,V;multiset<int64_t>a,b;main(){for(cin>>V>>K;cin>>V;)if(V<2){cin>>V;a.insert(-V);auto i=a.begin();a.size()<K||(b.insert(-*i),a.erase(i),0);}else{auto i=b.begin();cout<<(b.size()?(V=*i,b.erase(i),V):-1)<<endl;}}