题目描述
You are given N integers A_1, A_2, ..., A_N.
Consider the sums of all non-empty subsequences of A. There are 2^N - 1 such sums, an odd number.
Let the list of these sums in non-decreasing order be S_1, S_2, ..., S_{2^N - 1}.
Find the median of this list, S_{2^{N-1}}.
Constraints
- $1 \leq N \leq 2000$
- $1 \leq A_i \leq 2000$
- All input values are integers.
Input
Input is given from Standard Input in the following format:
N
A_1 A_2 ... A_N
Output
Print the median of the sorted list of the sums of all non-empty subsequences of A.
Examples
Input
3
1 2 1
Output
2
Input
1
58
Output
58
输入格式
见题面
输出格式
见题面
样例输入
3
1 2 1
样例输出
2