Problem: You are given an array a consisting of n integers (it is guaranteed that n is even, i.e. divisible by 2). All a_i does not exceed some integer k.

Your task is to replace the minimum number of elements (replacement is the following operation: choose some index i from 1 to n and replace a_i with some integer in range [1; k]) to satisfy the following conditions:

  * after all replacements, all a_i are positive integers not greater than k; 
  * for all i from 1 to n/2 the following equation is true: a_i + a_{n - i + 1} = x, where x should be the same for all n/2 pairs of elements. 



You have to answer t independent test cases.

Input

The first line of the input contains one integer t (1 ≤ t ≤ 10^4) — the number of test cases. Then t test cases follow.

The first line of the test case contains two integers n and k (2 ≤ n ≤ 2 ⋅ 10^5, 1 ≤ k ≤ 2 ⋅ 10^5) — the length of a and the maximum possible value of some a_i correspondingly. It is guratanteed that n is even (i.e. divisible by 2). The second line of the test case contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ k), where a_i is the i-th element of a.

It is guaranteed that the sum of n (as well as the sum of k) over all test cases does not exceed 2 ⋅ 10^5 (∑ n ≤ 2 ⋅ 10^5, ∑ k ≤ 2 ⋅ 10^5).

Output

For each test case, print the answer — the minimum number of elements you have to replace in a to satisfy the conditions from the problem statement.

Example

Input


4
4 2
1 2 1 2
4 3
1 2 2 1
8 7
6 1 1 7 6 3 4 6
6 6
5 2 6 1 3 4


Output


0
1
4
2

Solution (in JAVA):

Solution:
import java.io.*;
import java.nio.CharBuffer;
import java.util.*;

public class P1343D {

    public static void main(String[] args) {
        SimpleScanner scanner = new SimpleScanner(System.in);
        PrintWriter writer = new PrintWriter(System.out);

        int caseNum = scanner.nextInt();
        while (caseNum-- > 0) {
            int n = scanner.nextInt();
            int k = scanner.nextInt();
            int[] x = new int[n];
            for (int i = 0; i < n; ++i)
                x[i] = scanner.nextInt();
            TreeMap<Integer, Integer> sumCntMap = new TreeMap<>();
            ArrayList<Integer> min = new ArrayList<>(n);
            ArrayList<Integer> max = new ArrayList<>(n);
            for (int i = 0; i < n / 2; ++i) {
                int sum = x[i] + x[n - i - 1];
                sumCntMap.compute(sum, (t, v) -> v == null ? 1 : v + 1);
                min.add(Math.min(x[i], x[n - i - 1]));
                max.add(Math.max(x[i], x[n - i - 1]));
            }
            min.sort(Comparator.naturalOrder());
            max.sort(Comparator.naturalOrder());
            int ans = n / 2;
            int lt = 0;
            int nlt = 0;
            for (Map.Entry<Integer, Integer> entry : sumCntMap.entrySet()) {
                int sum = entry.getKey();
                int cnt = entry.getValue();
                if (sum <= k) {
                    while (lt < n / 2 && min.get(lt) < sum)
                        ++lt;
                    ans = Math.min(ans, n - cnt * 2 - (lt - cnt));
                } else {
                    while (nlt < n / 2 && max.get(nlt) < sum - k)
                        ++nlt;
                    ans = Math.min(ans, n - cnt * 2 - (n / 2 - cnt - nlt));
                }
            }
            writer.println(ans);
        }

        writer.close();
    }

    private static class SimpleScanner {

        private static final int BUFFER_SIZE = 10240;

        private Readable in;
        private CharBuffer buffer;
        private boolean eof;

        private SimpleScanner(InputStream in) {
            this.in = new BufferedReader(new InputStreamReader(in));
            buffer = CharBuffer.allocate(BUFFER_SIZE);
            buffer.limit(0);
            eof = false;
        }


        private char read() {
            if (!buffer.hasRemaining()) {
                buffer.clear();
                int n;
                try {
                    n = in.read(buffer);
                } catch (IOException e) {
                    n = -1;
                }
                if (n <= 0) {
                    eof = true;
                    return '\0';
                }
                buffer.flip();
            }
            return buffer.get();
        }

        private void checkEof() {
            if (eof)
                throw new NoSuchElementException();
        }

        private char nextChar() {
            checkEof();
            char b = read();
            checkEof();
            return b;
        }

        private String next() {
            char b;
            do {
                b = read();
                checkEof();
            } while (Character.isWhitespace(b));
            StringBuilder sb = new StringBuilder();
            do {
                sb.append(b);
                b = read();
            } while (!eof && !Character.isWhitespace(b));
            return sb.toString();
        }

        private int nextInt() {
            return Integer.parseInt(next());
        }

        private long nextLong() {
            return Long.parseLong(next());
        }

        private double nextDouble() {
            return Double.parseDouble(next());
        }
    }
}