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