Before you begin, you should try this problem! AVL Tree

This problem is simple. Initially, there is a list and it is empty. Then you are given four types of query:

1. Insert data to the list.
2. Remove data from the list.
3. Print an index (1-based) from a specified data after the list was sorted ascendingly.
4. Print data from a specified index (1-based) after the list was sorted ascendingly.

Input

Input contains several lines. Each line follows one of these formats.

• 1 n: Insert n (0 ≤ n ≤ 2³¹ - 1) to the list.
• 2 n: Remove n from the list. If n was not found, do nothing.
• 3 n: Print n's index (1-based) after the list was sorted ascendingly.
• 4 i: Print data at i-th index (1-based) after the list was sorted ascendingly (0 ≤ i ≤ 2³¹ - 1).
• -1: End of input.

Output

For each query 3, print n's index in one line. If n was not found, just print -1.

For each query 4, print data on i-th index in one line. If the index is not valid, just print -1.

Example

Input:
3 20
-1
Output:
-1