Score Ledger Rank Statistics

A scoring ledger maintains a multiset of scores, each an integer from 1 to 50. Starting empty, it processes q operations, each one of:

• INSERT x — add one occurrence of score x.
• ERASE x — remove one occurrence of score x. It is guaranteed at least one occurrence exists.
• RANK x — report how many scores currently in the multiset are strictly less than x.
• KTH k — report the k-th smallest score currently in the multiset (1-indexed, counting duplicates). It is guaranteed 1 <= k <= the current size.

Input format

Line 1: an integer q. Next q lines: INSERT x, ERASE x, RANK x, or KTH k.

Output format

For every RANK and every KTH operation, in order, print the requested integer on its own line.

Constraints

• 1 <= q <= 40
• 1 <= x <= 50
• 1 <= k <= current multiset size