1186 - SCU-F

Time Limit : 5 Second

Memory Limit : 128 MB

Submission: 74

Solved: 22

Description
Given a N-figures positive integer whose first figure is not 0.
You can remove M figures from it so the rest figures form a
(N-M)-figures positive integer whose first figure is not 0.
Can you tell me the minimal?
Input
The first line of the input is the number of test cases.
For each case there is two lines.
The first line contains two integers N and M.
The second line contains a N-figures positive integer
whose first figure is not 0.
( 0 <= M < N <= 10^5 )
There is a blank line before each test case.
Output
For each test case output the answer on a line.
sample input
4

2 1
90

9 3
123123123

11 1
90019008798

11 3
90019008798
sample output
9
112123
9001008798
19008798
hint
source
SCUPC
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