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
/*
[ ( ^ _ ^ ) ]
*/

// problem: cf/1335/E1

import java.io.*;
import java.util.*;


public class e1 {
    int INF = (int)1e9;
    long MOD = 1000000007;

    int max(int a, int b) {return a>=b?a:b;}
    int min(int a, int b) {return a<=b?a:b;}

    void solve(InputReader in, PrintWriter out) throws IOException {
        int n = in.nextInt();
        int[] a = new int[n+2];
        int[][] p = new int[n+2][30];
        int mx = 0;
        for(int i=1; i<=n; i++) {
            a[i] = in.nextInt();
            mx = max(mx, a[i]);
            p[i][a[i]] = 1;
            for(int j=1; j<=26; j++) {
                p[i][j] += p[i-1][j];
            }
        }
        int[][] s = new int[n+2][30];
        for(int i=n; i>=1; i--) {
            s[i][a[i]] = 1;
            for(int j=1; j<=mx; j++) {
                s[i][j] += s[i+1][j];
            }
        }
        int rs = 1;
        for(int i=0; i<=n; i++) {
            for(int j=1; j<i; j++) {
                if(a[i]!=a[j]) continue;
                // show("ij", i, j);
                int x = 0;
                for(int k=1; k<=mx; k++) {
                    x = max(x, p[i-1][k]-p[j][k]);
                }
                // show("x", x, a[i], p[j][a[i]], s[i][a[i]]);
                x += 2 * min(p[j][a[i]], s[i][a[i]]);
                rs = max(rs, x);
                // show("rs", rs);
            }
        }
        // show("--");
        out.println(rs);
    }
    

    public static void main(String[] args) throws IOException {
        InputReader in = new InputReader();
        PrintWriter out = new PrintWriter(System.out);
        int t = in.nextInt();
        while(t-- >0) {
            new e1().solve(in, out);
        }
        out.close();
    }
    
    public static void show(Object... o) {
        System.out.println(Arrays.deepToString(o));
    }
    
    static class InputReader {
        static BufferedReader br;
        static StringTokenizer st;
        public InputReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        String next() {
            while (st == null || !st.hasMoreTokens()) {
                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()); }
    }
}