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.util.*;
import java.io.*;
public class E634
{
    public static void main(String [] args)
    {
        MyScanner sc = new MyScanner();
        PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));
        int t = sc.nextInt();
        while (t > 0) {
            int n = sc.nextInt(); int [] a = new int [n];
            int max = 0; int [][] stor = new int [n][27];
            for (int i = 0; i < n; i++) a[i] = sc.nextInt();
            if (n == 1) {
                out.println(1); t--; continue;
            } else if (n == 2) {
                if (a[0] == a[1]) {
                    out.println(2);
                    t--; continue;
                }
                else {
                    out.println(1);
                    t--; continue;
                }
            }
            for (int i = 0; i < n; i++) {
                stor[i][a[i]] = 1;
            }
            for (int j = 1; j <= 26; j++) {
                for (int i = 1; i < n; i++) {
                    stor[i][j] = stor[i][j] + stor[i-1][j];
                }
            }
            int [] prefix = new int [n]; int [] suffix = new int [n];
            int [][] prefixTotal = new int [n][27]; int [][] suffixTotal = new int [n][27];
            for (int i = 0; i < n; i++) {
                int cur = 0;
                for (int j = 1; j <= 26; j++) {
                    cur = Math.max(cur, stor[i][j]);
                    prefixTotal[i][j] = stor[i][j];
                }
                prefix[i] = cur;
            }
            for (int i = 0; i < n; i++) {
                int cur = 0;
                for (int j = 1; j <= 26; j++) {
                    if (i != 0) {
                        cur = Math.max(cur, stor[n - 1][j] - stor[i - 1][j]);
                        suffixTotal[i][j] = stor[n - 1][j] - stor[i - 1][j];
                    }
                    else {
                        cur = Math.max(cur, stor[n - 1][j]);
                        suffixTotal[i][j] = stor[n - 1][j];
                    }
                }
                suffix[i] = cur;
            }
            int ans = 0;
            for (int i = 0; i < n ; i++) {
                for (int j = i + 1; j < n; j++) {
                    int middleMax = 0; int maxSides = 0;
                    for (int middle = 1; middle <= 26; middle++) {
                        if (stor[i][middle] == stor[n - 1][middle] - stor[j - 1][middle]) {
                            maxSides = Math.max(maxSides, 2 * stor[i][middle]);
                        }
                        middleMax = Math.max(middleMax, stor[j - 1][middle] - stor[i][middle]);
                    }
                    ans = Math.max(ans, middleMax + maxSides);
                }
            }
            out.println(ans);
            t--;
        }
        out.close();
    }


    //-----------MyScanner class for faster input----------
    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

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

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }



    }

}