#1396. 子集和的中位数

子集和的中位数

Problem Statement

You are given NN integers A1,A2,...,ANA_1, A_2, ..., A_N.

Consider the sums of all non-empty subsequences of AA. There are 2N12^N−1 such sums, an odd number.

Let the list of these sums in non-decreasing order be S1,S2,...,S2N1S_1, S_2, ..., S_{2^N−1}.

Find the median of this list, S2N1S_{2^N−1}.

Constraints

  • 1N20001≤N≤2000
  • 1Ai20001≤A_i≤2000
  • All input values are integers.

Input

Input is given from Standard Input in the following format:

N
A1 A2 ... AN

Output

Print the median of the sorted list of the sums of all non-empty subsequences of AA.


Sample Input 1

3
1 2 1

Sample Output 1

2

In this case, S=(1,1,2,2,3,3,4)S=(1,1,2,2,3,3,4). Its median is S4=2S_4=2.


Sample Input 2

1
58

Sample Output 2

58

In this case, S=(58)S=(58).