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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.StringTokenizer;

public class TaskE {
    public static String doMain(Reader reader) throws IOException {
        MyReader in = new MyReader(reader);
        int tests = in.nextInt();
        StringBuilder sb = new StringBuilder();
        for (int t = 0; t < tests; ++t) {
            int n = in.nextInt();
            int[] a = in.readIntArray(n);
            int[][] cnt = new int[26][n + 1];
            for (int i = 0; i < 26; ++i) {
                for (int j = 1; j < n + 1; ++j) {
                    cnt[i][j] += cnt[i][j - 1] + ((a[j - 1] == i + 1) ? 1 : 0);
                }
            }
            int max = 0;
            for (int num = 0; num < 26; ++num) {
                int l = 0;
                int r = n - 1;
                int x = 1;
                while (l < r) {
                    while (l < r && a[l] != num + 1) {
                        l++;
                    }
                    while (l < r && a[r] != num + 1) {
                        r--;
                    }
                    int max2 = 0;
                    int[] sum = new int[26];
                    for (int k = l + 1; k < r; ++k) {
                        sum[a[k] - 1]++;
                    }
                    for (int i : sum) {
                        max2 = Math.max(max2, i);
                    }
                    if (l<r) {
                        max = Math.max(max, max2 + 2 * x);
                    }
                    x++;
                    l++;
                    r--;
                }
            }
            sb.append(max==0?1:max).append("\n");
        }
        return sb.toString();
    }

    public static void main(String[] args) throws IOException {
        String result = doMain(new InputStreamReader(System.in));
        System.out.println(result);
    }

    static class MyReader {
        BufferedReader bf;

        StringTokenizer st;

        String last;

        MyReader(Reader reader) throws IOException {
            bf = new BufferedReader(reader);
            readNextLine();
        }

        String nextToken() throws IOException {
            while (!st.hasMoreTokens()) {
                readNextLine();
            }
            return st.nextToken();
        }

        void readNextLine() throws IOException {
            last = bf.readLine();
            if (last == null) last = "";
            st = new StringTokenizer(last);
        }

        String nextLine() throws IOException {
            String s = last;
            readNextLine();
            return s;
        }

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

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

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

        int[] readIntArray(int n) throws IOException {
            int[] answer = new int[n];
            for (int i = 0; i < n; ++i) {
                answer[i] = nextInt();
            }
            return answer;
        }

        long[] readLongArray(int n) throws IOException {
            long[] answer = new long[n];
            for (int i = 0; i < n; ++i) {
                answer[i] = nextLong();
            }
            return answer;
        }

        double[] readDoubleArray(int n) throws IOException {
            double[] answer = new double[n];
            for (int i = 0; i < n; ++i) {
                answer[i] = nextDouble();
            }
            return answer;
        }
    }
}
