HTMLify

class Solution:
    def removeKdig(self, s, k):
        if len(s) == k:
            return "0"
            
        stack = []
        for digit in s:
            while k > 0 and stack and stack[-1] > digit:
                stack.pop()
                k -= 1
            stack.append(digit)
        
        while k > 0:
            stack.pop()
            k -= 1
            
        res = "".join(stack).lstrip('0')
        return res if res else "0"