The only difference between easy and hard versions is constraints.

You are given a sequence a consisting of n positive integers.

Let's define a three blocks palindrome as the sequence, consisting of at most two distinct elements (let these elements are a and b, a can be equal b) and is as follows: [\underbrace{a, a, ..., a}_{x}, \underbrace{b, b, ..., b}_{y}, \underbrace{a, a, ..., a}_{x}]. There x, y are integers greater than or equal to 0. For example, sequences [], [2], [1, 1], [1, 2, 1], [1, 2, 2, 1] and [1, 1, 2, 1, 1] are three block palindromes but [1, 2, 3, 2, 1], [1, 2, 1, 2, 1] and [1, 2] are not.

Your task is to choose the maximum by length subsequence of a that is a three blocks palindrome.

You have to answer t independent test cases.

Recall that the sequence t is a a subsequence of the sequence s if t can be derived from s by removing zero or more elements without changing the order of the remaining elements. For example, if s=[1, 2, 1, 3, 1, 2, 1], then possible subsequences are: [1, 1, 1, 1], [3] and [1, 2, 1, 3, 1, 2, 1], but not [3, 2, 3] and [1, 1, 1, 1, 2].

Input

The first line of the input contains one integer t (1 ≤ t ≤ 2000) — the number of test cases. Then t test cases follow.

The first line of the test case contains one integer n (1 ≤ n ≤ 2000) — the length of a. The second line of the test case contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 26), where a_i is the i-th element of a. Note that the maximum value of a_i can be up to 26.

It is guaranteed that the sum of n over all test cases does not exceed 2000 (∑ n ≤ 2000).

Output

For each test case, print the answer — the maximum possible length of some subsequence of a that is a three blocks palindrome.

Example

Input


6
8
1 1 2 2 3 2 1 1
3
1 3 3
4
1 10 10 1
1
26
2
2 1
3
1 1 1


Output


7
2
4
1
1
3
import java.io.*;
import java.util.*;

public class Task5 {
    FastScanner scanner;
    PrintWriter writer;

    public final String INPUT_FILE_NAME = "input.txt";
    public final String OUTPUT_FILE_NAME = "output.txt";

    public void run() {
        try {
            writer = new PrintWriter(System.out);//new PrintWriter(new File(OUTPUT_FILE_NAME));
            scanner = new FastScanner(System.in);//new FastScanner(new File(INPUT_FILE_NAME));

            solution();

            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    class FastScanner {
        BufferedReader reader;

        StringTokenizer tokenizer;
        FastScanner(File file) throws FileNotFoundException {
            reader = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
        }

        FastScanner(InputStream is) {
            reader = new BufferedReader(new InputStreamReader(is));
        }

        boolean hasNext() {
            boolean result = false;
            if (tokenizer != null && tokenizer.hasMoreTokens()) {
                result =  true;
            } else {
                String newLine = null;
                try {
                    newLine = reader.readLine();
                    while(newLine != null) {
                        newLine = newLine.trim();
                        if (!newLine.equals("")) {
                            break;
                        }
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }

                if (newLine != null) {
                    result = true;
                    tokenizer = new StringTokenizer(newLine);
                }
            }

            return result;
        }

        String next() {
            hasNext();
            return tokenizer.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

    }

    public static void main(String[] args) {
        new Task5().run();
    }

    public StreamTokenizer st = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));

    public int nextInt() throws IOException {
        st.nextToken();
        return (int)st.nval;
    }

    public int[] nextIntArray(int n) throws IOException {
        int[] result = new int[n];
        for(int index = 0; index < n; ++index) {
            result[index] = nextInt();
        }
        return result;
    }

    public final static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

    public class cmp implements Comparator<Integer> {

        @Override
        public int compare(Integer o1, Integer o2) {
            int first = o1;
            int second = o2;
            return Integer.compare(Math.abs(first), Math.abs(second));
        }
    }

    public void solution() throws IOException {
        int t = nextInt();
        for (int i = 0; i < t; ++i) {
            int n = nextInt();
            int[] a = nextIntArray(n);
            solution(n, a);
        }
    }

    public void solution(int n, int[] array) {
        int result = 0;
        int[][] partSum = new int[27][n+1];
        for(int i = 0; i < n; ++i) {
            partSum[array[i]][i+1] = 1;
        }
        for(int i = 1; i <= 26; ++i) {
            for(int j = 1; j <= n; ++j) {
                partSum[i][j] += partSum[i][j-1];
            }
        }

        for(int i = 1; i <= n; ++i) {
            for(int j = i; j <= n; ++j) {
                result = Math.max(result,
                        maxY(n, partSum, i, j) +
                        2 * maxX(n, partSum, 1, i-1, j + 1, n));
            }
        }
        System.out.println(result);
    }

    public int maxX(int n, int[][] partSum, int l1, int r1, int l2, int r2) {
        int result = 0;
        if (l1 <= r1 && l2 <= r2) {
            for(int i = 1; i <= 26; ++i) {
                int temp = Math.min(partSum[i][r1] - partSum[i][l1-1],
                                    partSum[i][r2] - partSum[i][l2-1]);
                result = Math.max(result, temp);
            }
        }
        return result;
    }

    public int maxY(int n, int[][] partSum, int l, int r) {
        int result = 0;
        for(int i = 1; i <= 26; ++i) {
            int temp = partSum[i][r] - partSum[i][l-1];
            result = Math.max(result, temp);
        }
        return result;
    }
}
