Alphabetically smallest word

Given a string $s$ made up of only lowercase letters, and a natural number $k$ , remove any substring of length $k$ from $s$ so that the result is the lexicographically smallest possible word.

Input

Input consists of several cases, each with $s$ and $k$ . Assume $1 \le k < \vert s \vert \le 10^4$ .

Output

For every case, print the alphabetically smallest word that can be obtained after removing $k$ consecutive letters from $s$ .

Problem information

Author: Salvador Roura

Generation: 2026-01-25T12:01:57.312Z