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

T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;

void main() {
    auto qk = readints;
    int q = qk[0], k = qk[1];

    auto q1 = new BinaryHeap!(Array!long);
    auto q2 = new BinaryHeap!(Array!long);
    for (int i = 0; i < q; i++) {
        auto xs = reads!long;
        if (xs.length > 1) {
            q1.insert(xs[1]);
            if (q1.length > k) {
                q2.insert(q1.front);
                q1.popFront;
            }
        }
        else {
            if (q1.length < k) {
                writeln(-1);
            }
            else {
                writeln(q1.front);
                q1.popFront;
                if (q2.length > 0) {
                    q1.insert(q2.front);
                    q2.popFront;
                }
            }
        }
   }
}