Input
=====

An integer n in the range 100 to 10^18 and an integer k in the range 1 to 18, inclusive.

The swap operation
==================

A swap chooses two digits at different positions and exchanges their positions, as long as the swap does not result in a leading zero. For example if we start with the integer `12345` we can perform one swap to make it `12543`.

Task
====

Output the largest number you can get after exactly k swaps.

Examples
========

```
n = 1283, k = 2. Output: 8312
n = 510, k = 1. Output: 501
n = 501, k = 2. Output: 501
n = 999, k = 3. Output: 999
n = 12345678987654321, k = 1. Output: 92345678187654321

```