Implement a priority queue

You have to implement the pop function of Max Priority Queue and implement using a heap.

Functions :

a) push(int x) : 'x' has to be inserted in the priority queue. This has been implemented already

b) pop() : return the maximum element in the priority queue, if priority queue is empty then return '-1'.

Example:

We perform the following operations on an empty priority queue:

When operation push(5) is performed, we insert 1 in the priority queue.

When operation push(2) is performed, we insert 2 in the priority queue. 

When operation pop() is performed, we remove the maximum element from the priority queue and print which is 5.

When operation push(3) is performed, we insert 1 in the priority queue.

When operation pop() is performed, we remove the maximum element from the priority queue and print which is 3.

Input Format:

The first line of contains a single integer, ‘n’ , representing the  number of operations.

The next ‘n’ lines of each test case contain operations that have to be performed on the stack. 

Operations of the format
1 x : denotes to perform the operation push(x).
2 : denotes to perform the operation pop(). 

Output Format :

Print output of each query in a separate line.

Note :

You do not need to print anything. It has already been taken care of. Just implement the given function.