class Solution {
    public String solution(String number, int k) {

        int count = k;
        int index = 0;
        StringBuilder sb = new StringBuilder(number);

        while (count != 0 && index != sb.length() - 1) {
            char currentNum = sb.charAt(index);
            char nextNum = sb.charAt(index + 1);

            if (currentNum >= nextNum) {
                index++;
            } else {
                sb.deleteCharAt(index);
                count--;

                if (index != 0) {
                    index--;
                }
            }
        }
        
         // 남아있는 모든 숫자가 같거나 내림차순인 경우
        if (count != 0) {
            sb.delete(sb.length() - count, sb.length());
        }

        return sb.toString();
    }
}