Score : $1000$ points

Problem Statement

You are given a string $S$ consisting of digits between 1 and 9, inclusive. You will insert at most $K$ commas (,) into this string to separate it into multiple numbers.

Your task is to minimize the maximum number among those produced by inserting commas. Find minimum possible such value.

Constraints

• $0 \leq K < |S| \leq 100,000$
• $S$ consists of digits between 1 and 9, inclusive.

Partial Scores

• In the test set worth $100$ points, $|S| \leq 2$.
• In the test set worth another $100$ points, $|S| \leq 16$.
• In the test set worth another $200$ points, $|S| \leq 100$.
• In the test set worth another $200$ points, $|S| \leq 2,000$.

Input

The input is given from Standard Input in the following format:

$K$

$S$

Output

Print the minimum possible value.

2
15267315

315

When the string is separated into $152$, $67$ and $315$, the maximum among these is $315$, which is the minimum possible value.

0
12456174517653111

12456174517653111

$12456174517653111$ itself is the answer.

8
127356176351764127645176543176531763517635176531278461856198765816581726586715987216581

5317635176