## Problem Description

Rar the Cat is trying out his new correction tape. He takes a sheet of paper, containing an N-digit integer, and decides to remove K of these digits. The remaining digits will join together to form a new integer with N - K digits.

Help Rar find the minimum possible integer he can form. Note that the resultant integer cannot have leading zeroes.

## Input

The first line of input will contain two integers, N and K.

The second line of input will contain one integer, representing the original integer Rar has.

## Output

Output a single line containing one integer, the minimum possible resultant integer Rar can form.

## Limits

1 ≤ K < N.

Subtask 1 (8%): 2 ≤ N ≤ 16.

Subtask 2 (12%): 2 ≤ N ≤ 2 000. Each digit in the integer will be a 0 or a 1.

Subtask 3 (14%): 2 ≤ N ≤ 2 000.

Subtask 4 (6%): 2 ≤ N ≤ 100 000. K = N - 1.

Subtask 5 (16%): 2 ≤ N ≤ 100 000. Each digit in the integer will be a 0 or a 1.

Subtask 6 (18%): 2 ≤ N ≤ 100 000. No digit in the original integer will be a 0.

Subtask 7 (15%): 2 ≤ N ≤ 100 000.

Subtask 8 (11%): 2 ≤ N ≤ 5 000 000.

```5 3
23195
```

```15
```

```10 6
9031193452
```

```1132
```

## Sample Testcase 3

```5 2
10101
```

```100
```

### Submitting .cpp to 'blanko'

Time Limit: 1 Seconds
Memory Limit: 128MB
No. of ACs: 10