CF1197A.DIY Wooden Ladder

传统题 时间 2000 ms 内存 256 MiB 4 尝试 1 已通过 1 标签

DIY Wooden Ladder

Let's denote a kk-step ladder as the following structure: exactly k+2k + 2 wooden planks, of which

  • two planks of length at least k+1k+1 — the base of the ladder;
  • kk planks of length at least 11 — the steps of the ladder;

Note that neither the base planks, nor the steps planks are required to be equal.

For example, ladders 11 and 33 are correct 22-step ladders and ladder 22 is a correct 11-step ladder. On the first picture the lengths of planks are [3,3][3, 3] for the base and [1][1] for the step. On the second picture lengths are [3,3][3, 3] for the base and [2][2] for the step. On the third picture lengths are [3,4][3, 4] for the base and [2,3][2, 3] for the steps.

You have nn planks. The length of the ii-th planks is aia_i. You don't have a saw, so you can't cut the planks you have. Though you have a hammer and nails, so you can assemble the improvised "ladder" from the planks.

The question is: what is the maximum number kk such that you can choose some subset of the given planks and assemble a kk-step ladder using them?

Input

The first line contains a single integer TT (1T1001 \le T \le 100) — the number of queries. The queries are independent.

Each query consists of two lines. The first line contains a single integer nn (2n1052 \le n \le 10^5) — the number of planks you have.

The second line contains nn integers a1,a2,,ana_1, a_2, \dots, a_n (1ai1051 \le a_i \le 10^5) — the lengths of the corresponding planks.

It's guaranteed that the total number of planks from all queries doesn't exceed 10510^5.

Output

Print TT integers — one per query. The ii-th integer is the maximum number kk, such that you can choose some subset of the planks given in the ii-th query and assemble a kk-step ladder using them.

Print 00 if you can't make even 11-step ladder from the given set of planks.

Note

Examples for the queries 131-3 are shown at the image in the legend section.

The Russian meme to express the quality of the ladders:

Samples

4
4
1 3 1 3
3
3 3 2
5
2 3 3 4 2
3
1 1 2
2
1
2
0

在线编程 IDE

建议全屏模式获得最佳体验