atcoder#AGC020C. [AGC020C] Median Sum

[AGC020C] Median Sum

Score : 700700 points

Problem Statement

You are given NN integers A1A_1, A2A_2, ..., ANA_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 S1S_1, S2S_2, ..., S2N1S_{2^N - 1}.

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

Constraints

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

Input

Input is given from Standard Input in the following format:

NN

A1A_1 A2A_2 ...... ANA_N

Output

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

3
1 2 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.

1
58
58

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