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.util.*;
import java.math.*;
public class Euler {

	static FastReader in;
	static PrintWriter o;

	public static void solve() {
		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[][] pref = new int[n+1][27];
			for (int i = 1; i <= n; i++) {
				int x = arr[i-1];
				for (int j = 1; j <= 26; j++) {
					pref[i][j] = pref[i-1][j];
				}
				pref[i][x]++;
			}

			int ans = 0;
			for (int i = 1; i <= 26; i++) {
				if (pref[n][i] > ans) {
					ans = pref[n][i];
				}
			}
			for (int i = 2; i < n; i++) {
				for (int j = i; j < n; j++) {

//					if (i == 3 && j == 6) {
//						o.println(pref[i][1] + " " + (pref[j][2]-pref[i-1][2]) + " " + (pref[n][1]-pref[j][1]));
//					}

					int max1 = 0;
					for (int k = 1; k <= 26; k++) {
						if (max1 < pref[j][k] - pref[i-1][k]) {
							max1 = pref[j][k] - pref[i-1][k];
						}
					}
					int max2 = 0;
					for (int k = 1; k <= 26; k++) {
						int val = Math.min(pref[i-1][k], pref[n][k] - pref[j][k]);
						if (val > max2) {
							max2 = val;
						}
					}
					if (max2 * 2 + max1 > ans) {
						ans = max2 * 2 + max1;
					}

				}
			}
			o.println(ans);
		}
		o.close();
		return;


	}

	public static void main(String[] args) {
		in = new FastReader();
		o = new PrintWriter(System.out);
		solve();
		return;
	}

	static class FastReader {
		BufferedReader br;
		StringTokenizer st;

		public FastReader() {
			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());
		}

		int[] readArray(int n) {
			int[] a = new int[n];
			for (int i = 0; i < n; i++) a[i] = nextInt();
			return a;
		}

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

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

}