**Time limit:**1.00 s**Memory limit:**512 MB

**Input**

The first input line has an integer $n$: the number of apples.

The next line has $n$ integers $p_1,p_2,\dots,p_n$: the weight of each apple.

**Output**

Print one integer: the minimum difference between the weights of the groups.

**Constraints**

- $1 \le n \le 20$

- $1 \le p_i \le 10^9$

**Example**

Input:

`5`

3 2 7 4 1

Output:

`1`

Explanation: Group 1 has weights 2, 3 and 4 (total weight 9), and group 2 has weights 1 and 7 (total weight 8).