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 ≦ K < |S| ≦ 100,000
• S consists of digits between 1 and 9, inclusive.

Input

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

K
S

Output

Print the minimum possible value.

Examples

Input

2
15267315

Output

315

Input

0
12456174517653111

Output

12456174517653111

Input

8
127356176351764127645176543176531763517635176531278461856198765816581726586715987216581

Output

5317635176

见题面

见题面