import std.stdio;
import std.range;
import std.array;
import std.string;
import std.conv;
import std.typecons;
import std.algorithm;
import std.container;

void main()
{
  auto val = readln.chomp.split.map!(to!int);
  int q = val.front;
  int k = val.back;
  alias TreeOne = RedBlackTree!(ulong, "a < b", true);
  TreeOne treeLeft = new TreeOne();
  TreeOne treeRight = new TreeOne();
  foreach (i; 0..q) {
    auto wal = readln.chomp.split.map!(to!ulong);
    if (wal.front == 1) {
      auto trg = wal.back;
      treeLeft.insert(trg);
      if (treeLeft.length > k) {
        auto dst = treeLeft.back;
        treeLeft.removeKey = dst;
        treeRight.insert(dst);
      }
    } else {
      auto l = treeLeft.length;
      if (l < k) {
        writeln = -1;
        continue;
      }
      auto v = treeLeft.back;
      treeLeft.removeKey = v;
      if (treeRight.length) {
        auto w = treeRight.front;
        treeRight.removeKey = w;
        treeLeft.insert(w);
      }
      v.writeln;
    }
  }
}