题目描述
A priority queue is a data structure which maintains a set $S$ of elements, each of with an associated value (key), and supports the following operations:
- $insert(S, k)$: insert an element $k$ into the set $S$
- $extractMax(S)$: remove and return the element of $S$ with the largest key
Write a program which performs the $insert(S, k)$ and $extractMax(S)$ operations to a priority queue $S$. The priority queue manages a set of integers, which are also keys for the priority.
Constraints
- The number of operations $\leq 2,000,000$
- $0 \leq k \leq 2,000,000,000$
Input
Multiple operations to the priority queue $S$ are given. Each operation is given by "insert $k$", "extract" or "end" in a line. Here, $k$ represents an integer element to be inserted to the priority queue.
The input ends with "end" operation.
Output
For each "extract" operation, print the element extracted from the priority queue $S$ in a line.
Example
Input
insert 8
insert 2
extract
insert 10
extract
insert 11
extract
extract
end
Output
8
10
11
2
输入格式
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输出格式
见题面