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.*;

import static java.lang.Math.*;

public class Main {
    static void run() throws IOException {
        file("", "");
        int t = nextInt();
        while (t-- > 0)
            solution();
        end();
    }

    static void solution() throws IOException {
        TreeMap<Integer, Integer> fromleft = new TreeMap<>();
        TreeMap<Integer, Integer> fromright = new TreeMap<>();
        for (int i = 1; i <= 26; i++) {
            fromleft.put(i, 0);
            fromright.put(26 - i + 1, 0);
        }
        int n = nextInt();
        TreeMap<Integer, Integer>[] tms = new TreeMap[n];
        int[] arr = new int[n];
        for (int i = 0; i < n; i++)
            arr[i] = nextInt();
        for (int i = n - 1; i >= 0; i--) {
            fromright.put(arr[i], fromright.get(arr[i]) + 1);
            tms[i] = new TreeMap<>();
            for (Map.Entry<Integer, Integer> y : fromright.entrySet())
                tms[i].put(y.getKey(), y.getValue());
        }
        int max = 0;
        for (int i = 0; i < n; i++) {
            fromleft.put(arr[i], fromleft.get(arr[i]) + 1);
            int main = arr[i];
            int cnt = 1;
            for (int j = i + 1; j < n; j++) {
                if (arr[j] == main) {
                    cnt++;
                } else
                    max = max(max, cnt + 2 * min(fromleft.get(arr[j]), tms[j].get(arr[j])));
            }
            max = max(max, cnt);
        }
        out.println(max);
    }


    static long pow(long a, long b) {
        long h = 1;
        while (b > 0) {
            if (b % 2 != 0) {
                h *= a;
                b--;
            }
            b /= 2;
            a *= a;
        }
        return h;
    }

    static long lcm(long a, long b) {
        return a * b / gcd(a, b);
    }

    static long gcd(long a, long b) {
        return b == 0 ? a : gcd(b, a % b);
    }

    static void end() {
        out.flush();
        out.close();
    }

    static BufferedReader br;
    static PrintWriter out;

    static void file(String input, String output) {
        if (input.equals("")) {
            br = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
        } else {
            try {
                br = new BufferedReader(new FileReader(input));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            try {
                out = new PrintWriter(output);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }
    }

    static StringTokenizer in = new StringTokenizer("");

    public static String nextToken() throws IOException {
        while (in == null || !in.hasMoreTokens()) {
            String s = br.readLine();
            if (s == null) return null;
            in = new StringTokenizer(s);
        }
        return in.nextToken();
    }


    public static int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    public static double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }

    public static long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    public static void main(String[] args) throws IOException {
        run();

    }

}