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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Hola solver = new Hola();
        solver.solve(1, in, out);
        out.close();
    }

    static class Hola {
        PrintWriter out;
        InputReader in;
        long mod = (long)1e9 + 7;

        public void solve(int testNumber, InputReader in, PrintWriter out) {
            this.out = out;
            this.in = in;
            int t = ni();
            while(t-->0) {
                int n = ni();
                int[] arr = new int[n + 1];
                int i = 0, j = 0;
                int[][] cnt = new int[27][n + 1];
                for (i = 1; i <= n; i++) {
                    arr[i] = ni();
                    cnt[arr[i]][i]++;
                }
                for(i = 0; i < 27; i++){
                    for(j = 1; j <= n; j++)
                        cnt[i][j] += cnt[i][j - 1];
                }
                int[] freq = new int[27];
                int[][] rev = new int[27][n + 1];

                for(i = n; i >= 1; i--){
                    freq[arr[i]]++;
                    rev[arr[i]][freq[arr[i]]] = i;
                }
                Arrays.fill(freq, 0);
                int ans = 0;
                for (i = 1; i <= n; i++) {
                    freq[arr[i]]++;
                    for(j = 1; j <= 26; j++){
                        int id = rev[j][freq[j]];
                        if(id <= i)
                            continue;
                        int max = 0;
                        for(int k = 1; k <= 26; k++)
                            max = Math.max(max, cnt[k][id - 1] - cnt[k][i]);
                        ans = Math.max(ans, 2 * freq[j] + max);
                    }
                }
                for(j = 1; j <= 26; j++)
                    ans = Math.max(ans, freq[j]);
                pn(ans);
            }
        }
        void sort(int[] A){
            PriorityQueue<Integer> pq = new PriorityQueue();
            int i = 0;
            for(i = 0; i < A.length; i++)
                pq.add(A[i]);
            for(i = 0; i < A.length; i++)
                A[i] = pq.poll();
        }
        int gcd(int a, int b)
        {
            if (a == 0)
                return b;

            return gcd(b%a, a);
        }
        long mul(long a,long b){
            if(a>=mod)a%=mod;
            if(b>=mod)b%=mod;
            a*=b;
            if(a>=mod)a%=mod;
            return a;
        }
        long modPow(long a, long p){
            long o = 1;
            while(p>0){
                if((p&1)==1)o = mul(o,a);
                a = mul(a,a);
                p>>=1;
            }
            return o;
        }
        final Comparator<Tuple> com = new Comparator<Tuple>() {
            @Override
            public int compare(Tuple t1, Tuple t2) {
                if(t1.x != t2.x)
                    return Long.compare(t1.x, t2.x);
                else
                    return Long.compare(t2.y, t1.y);
            }
        };
        class Tuple{
            int x, y;
            Tuple(int x, int y){
                this.x = x;
                this.y = y;
            }
        }
        int ni() {
            return in.nextInt();
        }
        long nl() {
            return in.nextLong();
        }
        void pn(Object o) {
            out.println(o);
        }
        void p(Object o) {
            out.print(o);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1)
                throw new UnknownError();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new UnknownError();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }

        public String next() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuffer res = new StringBuffer();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));

            return res.toString();
        }

        private boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

    }
}
