## Problem Description

Yu Peng the Penguin is taking photos with his penguin friends today! Penguins have white bellies and black wings
and back, and as penguins are more or less of the same height, the photos taken can be represented as a binary
string, where '0' denotes a black pixel and '1' denotes a white pixel.

Yu Peng has taken *T* photos, where the *i*th photo is of length *N*_{i}. He tells you
that in the *i*th photo, there are at most *K*_{i} penguins. Yu Peng recognises a penguin as
a contiguous segment of white pixels (penguin with belly facing front), or a contiguous segment of black pixels
(penguin with back facing front), both of arbitrary length. However, some naughty penguins faced the camera sideways when
the photos were taken, and hence, there may be more than *K*_{i} penguins in the *i*th photo,
according to Yu Peng's rules.

Yu Peng is not happy with these naughty penguins and wants to edit the photos. He wonders, for the *i*th
photo, what is the minimum number of pixels that he has to change the colour of, such that he sees at most
*K*_{i} penguins in the photo.

## Input

The first line contains a single integer *T*, the number of photos.

Then, there are *T* pairs of lines, each describing a single photo taken.

For the *i*th pair of lines:

The first line contains two integers *N*_{i} and *K*_{i}.

The second line contains a binary string of length *N*_{i}.

## Output

Output *T* lines. The *i*th line should contain a binary string of length *N*_{i},
describing the *i*th edited photo, according to Yu Peng's requirements.

If there are several possible optimal edited photos, output any of them.

## Limits

Subtask 1 (11%): 1 ≤ *K*_{i} ≤ *N*_{i} ≤ 10. 1 ≤ ∑ *N*_{i} ≤ 5000.

Subtask 2 (24%): 1 ≤ *K*_{i} ≤ *N*_{i} ≤ 100. 1 ≤ ∑ *N*_{i} ≤ 5000.

Subtask 3 (24%): 1 ≤ *K*_{i} ≤ *N*_{i} ≤ 1000. 1 ≤ ∑ *N*_{i} ≤ 50 000.

Subtask 4 (21%): 1 ≤ *K*_{i} ≤ 5000. 1 ≤ ∑ *N*_{i} ≤ 100 000.

Subtask 5 (20%): 1 ≤ *K*_{i} ≤ 200 000. 1 ≤ ∑ *N*_{i} ≤ 200 000.

Subtask 6 (0%): Sample Testcases

## Sample Testcase 1

### Input

3
9 3
000111000
10 3
0111011010
4 4
0001

### Output

000111000
0111111000
0001