C. Alphabetic Removalstime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputYou 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.InputThe 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.OutputPrint 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).ExamplesInput15 3cccaabababaccbcOutputcccbbabaccbcInput15 9cccaabababaccbcOutputccccccInput1 1uOutput
Input15 3cccaabababaccbc
Outputcccbbabaccbc
['implementation', '*1200']