Box Loading Problem

Problem Background

Special for beginners, ^_^

Problem Description

There is a box of capacity $v$ (a positive integer, $0 \le v \le 20000$), and at the same time there are $n$ items ($0 < n \le 30$), each with a volume (a positive integer).

You are to pick some of the $n$ items to put into the box, so that the remaining space in the box is minimized.

Input Format

The capacity $v$ of the box.

The number of items $n$.

The next $n$ lines, each giving the volume of one of the $n$ items.

Output Format

The remaining space in the box.

Sample Input

24
6
8
3
12
7
9
7

Sample Output

0

Constraints

Time limit: 1s, memory limit: 1024KiB for each test case.