Alphabetic Removals
Description
You are given a string $s$ consisting of $n$ lowercase Latin letters. Polycarp wants to remove exactly $k$ characters ($k \le n$) from the string $s$. Polycarp uses the following algorithm $k$ times:
- if there is at least one letter 'a', remove the leftmost occurrence and stop the algorithm, otherwise go to next item;
- if there is at least one letter 'b', remove the leftmost occurrence and stop the algorithm, otherwise go to next item;
- ...
- remove the leftmost occurrence of the letter 'z' and stop the algorithm.
This algorithm removes a single letter from the string. Polycarp performs this algorithm exactly $k$ times, thus removing exactly $k$ characters.
Help Polycarp find the resulting string.
The first line of input contains two integers $n$ and $k$ ($1 \le k \le n \le 4 \cdot 10^5$) — the length of the string and the number of letters Polycarp will remove.
The second line contains the string $s$ consisting of $n$ lowercase Latin letters.
Print the string that will be obtained from $s$ after Polycarp removes exactly $k$ letters using the above algorithm $k$ times.
If the resulting string is empty, print nothing. It is allowed to print nothing or an empty line (line break).
Input
The first line of input contains two integers $n$ and $k$ ($1 \le k \le n \le 4 \cdot 10^5$) — the length of the string and the number of letters Polycarp will remove.
The second line contains the string $s$ consisting of $n$ lowercase Latin letters.
Output
Print the string that will be obtained from $s$ after Polycarp removes exactly $k$ letters using the above algorithm $k$ times.
If the resulting string is empty, print nothing. It is allowed to print nothing or an empty line (line break).
Samples
15 3
cccaabababaccbc
cccbbabaccbc
15 9
cccaabababaccbc
cccccc
1 1
u