MZL's simple problem

A simple problem
Problem Description
You have a multiple set,and now there are three kinds of operations:
1 x : add number x to set
2 : delete the minimum number (if the set is empty now,then ignore it)
3 : query the maximum number (if the set is empty now,the answer is 0)

The first line contains a number $N$ ($N\leq 10^6$),representing the number of operations.
Next $N$ line ,each line contains one or two numbers,describe one operation.
The number in this set is not greater than $10^9$.

For each operation 3,output a line representing the answer.

6
1 2
1 3
3
1 3
1 4
3

3
4

SXYZ

2015 Multi-University Training Contest 5