What is Spenser's favorite integer?

Ask Amplitude claims that Spenser's favorite integer is ~integerGuess~. It turns out that this is almost correct - Ask Amplitude has hallucinated some additional digits.

We know that Spenser's favorite integer has exactly ~length~ digits, and Spenser's favorite integer is the largest integer that can be derived after deleting enough digits from ~integerGuess~ to be exactly the right length.

Constraints

~1 \le length \le |integerGuess| \le 10^6~

Subtask 1 [1 point]

~|integerGuess| \le 10~

Subtask 2 [1 point]

~|integerGuess| \le 10^3~

Subtask 3 [1 point]

No additional constraints.

Input Specification

The first line contains a single integer, ~length~.

The next line contains ~integerGuess~, the integer that Ask Amplitude generated.

Output Specification

Output a single integer, Spenser's favorite integer.

Sample Input 1

3
8567

Sample Output 1

867

Sample Input 2

3
2671

Sample Output 2

671