A warehouse serial code is a string of n decimal digits (it may itself start with a digit 0). You must remove exactly k of its digits, keeping the remaining digits in their original relative order, to form a new digit string that is as numerically small as possible. After removing the digits, strip any leading zeros from the result; if the result would then be empty, the answer is 0.
Input format
Line 1: two integers n and k.
Line 2: the serial code, a string of exactly n decimal digit characters (no spaces).
Output format
A single line: the numerically smallest possible result after removing exactly k digits and stripping leading zeros (or 0 if the result is empty).
Constraints
- 1 ≤ n ≤ 100000
- 0 ≤ k ≤ n