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 java.lang.*;

public class Main implements Runnable {
    public static void main(String[] args) {
        new Thread(null, new Main(), "Check2", 1 << 28).start();// to increse stack size in java
    }
    // CandidateCode
    static long mod = (long) (1e9 + 7);
    public void run() {
        InputReader in = new InputReader(System.in);
        PrintWriter w = new PrintWriter(System.out);

        int t = in.nextInt();

        while (t-- > 0){
            int n = in.nextInt();
            int arr[] = new int[n];
            for (int i=0;i<n;i++)arr[i] = in.nextInt();
            int res = 0;

            int dp[][] = new int[27][n+1];
            int rev[][] = new int[27][n+1];
            int prf[][] = new int[27][n+1];
            for (int i=0;i<=26;i++)Arrays.fill(dp[i],-1);

            for (int val=0;val<=26;val++){
                int count = 0;
                for (int j=0;j<n;j++){
                    if (arr[j] == val) {
                        count++;
                        dp[val][count] = j;
                    }
                    prf[val][j] = count;
                }
                count = 0;
                for (int j=n-1;j>=0;j--){
                    if (arr[j] == val) {
                        count++;
                        rev[val][count] = j;
                    }
                }
            }

            int finAns = 1;
            for (int x=1;x<=26;x++){
                for (int y=1;y<=26;y++){
                     for (int count = 0; count <= n;count++){
                         int leftMax = dp[x][count];
                         int rightMin = rev[x][count];
                         if (leftMax == - 1 || rightMin == -1 || leftMax >= rightMin)continue;
                         int ans = 2 * count;
                         if (rightMin-1>=leftMax){
                             ans += prf[y][rightMin-1] - prf[y][leftMax];
                         }
                         finAns = Math.max(finAns,ans);
                     }
                }
            }
            w.println(finAns);
        }
        w.close();
    }
    class pair implements Comparable<pair>{
        int id,val;
        pair(int id,int val){
            this.id = id;
            this.val = val;
        }
        public int compareTo(pair o){
            return this.val != o.val ? -(this.val - o.val) : this.id - o.id;
        }
    }
    void debug(Object...args) {
        System.out.println(Arrays.deepToString(args));
    }
    long modinv(long a,long b) {
        long p=power(b,mod-2,mod);
        p=a%mod*p%mod;
        p%=mod;
        return p;
    }
    long power(long x,long y,long mod){
        if(y==0)return 1%mod;
        if(y==1)return x%mod;
        long res=1;
        x=x%mod;
        while(y>0)
        {
            if((y%2)!=0){
                res=(res*x)%mod;
            }
            y=y/2;
            x=(x*x)%mod;
        }
        return res;
    }
    long gcd(long a,long b){

        if(b==0)return a;
        return gcd(b,a%b);
    }
    void sev(int a[],int n){

        for(int i=2;i<=n;i++)a[i]=i;
        for(int i=2;i<=n;i++){

            if(a[i]!=0){
                for(int j=2*i;j<=n;){

                    a[j]=0;
                    j=j+i;
                }
            }

        }

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

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

        public int read()
        {
            if (numChars==-1)
                throw new InputMismatchException();

            if (curChar >= numChars){
                curChar = 0;
                try
                {
                    numChars = stream.read(buf);
                }
                catch (IOException e)
                {
                    throw new InputMismatchException();
                }

                if(numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public String nextLine()
        {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String stock = "";
            try
            {
                stock = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return stock;
        }
        public int nextInt()
        {
            int c = read();

            while(isSpaceChar(c))
                c = read();

            int sgn = 1;

            if (c == '-')
            {
                sgn = -1;
                c = read();
            }

            int res = 0;
            do
            {
                if(c<'0'||c>'9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));

            return res * sgn;
        }

        public long nextLong()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            long res = 0;

            do
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        }

        public double nextDouble()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.')
            {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.')
            {
                c = read();
                double m = 1;
                while (!isSpaceChar(c))
                {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }

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

            return res.toString();
        }

        public boolean isSpaceChar(int c)
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next()
        {
            return readString();
        }

        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
    }
}
