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.util.*;

public class C1343PD {
    //static String probName = "template";
    static Comparator<int[]> comp = new Comparator<int[]>() {
        public int compare(int[] a, int[] b) {
            for (int i=0; i<a.length; i++) {
                if (a[i] < b[i])       return -1;
                else if (a[i] > b[i])  return 1;
            }
            return 0;
        }
    };
    static final long LARGE_LONG = 1000000000000000000L;
    static final int LARGE_INT = 1000000007;
    static final int[] dx = new int[] {1, -1, 0, 0};
    static final int[] dy = new int[] {0, 0, 1, -1};

    public static void main(String[] argst) throws IOException {
        FastReader in = new FastReader();
        // FastReader in = new FastReader(probName + ".in");
        // Scanner in = new Scanner(System.in);

        // PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter(probName + ".out")));
        PrintWriter out = new PrintWriter(System.out);
        int t = in.nextInt();
        for (int tc = 0; tc < t; tc ++) {
            int n = in.nextInt();
            int k = in.nextInt();
            int hf = n/2;
            int[] nums = new int[n];
            for (int i = 0; i < n; i++) {
                nums[i] = in.nextInt();
            }
            int[] da = new int[2*k+2];
            for (int i = 0; i < hf; i++) {
                int l = nums[i];
                int r = nums[n-1-i];
                int lb = Math.min(l, r) + 1;
                int ub = Math.max(l, r) + k;
                da[lb]--;
                da[l + r]--;
                da[l + r + 1]++;
                da[ub+1]++;
            }
            int mc = Integer.MAX_VALUE;
            int sm = n;
            for (int i = 2; i <= 2*k+1; i++) {
                sm += da[i];
                mc = Math.min(mc, sm);
            }
            out.println(mc);
        }
        out.close();
    }
    static class FenwickTree {
        int[] bit;  // binary indexed tree
        int n;

        public FenwickTree(int n) {
            this.n = n;
            bit = new int[n];
        }

        int sum(int r) {
            int ret = 0;
            for (; r >= 0; r = (r & (r + 1)) - 1)
                ret += bit[r];
            return ret;
        }

        int sum(int l, int r) {
            return sum(r) - sum(l - 1);
        }

        void add(int idx, int delta) {
            for (; idx < n; idx = idx | (idx + 1))
                bit[idx] += delta;
        }
    };


    /* FastReader code from  https://www.geeksforgeeks.org/fast-io-in-java-in-competitive-programming/
       nextLine modified, and added next(), and hasNext()
    */
    static class FastReader {
        final private int BUFFER_SIZE = 1 << 16;
        final private int MAX_LINE_SIZE = 1 << 20;
        private DataInputStream din;
        private byte[] buffer, lineBuf;
        private int bufferPointer, bytesRead;

        public FastReader() {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }
        public FastReader(String file_name) throws IOException {
            din = new DataInputStream(new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }
        public boolean hasNext() throws IOException {
            byte c;
            while ((c = read()) != -1) {
                if (c > ' ') {
                    bufferPointer--;
                    return true;
                }
            }
            return false;
        }
        public String nextLine() throws IOException {
            if (lineBuf == null)	lineBuf = new byte[MAX_LINE_SIZE];
            int ctr = 0;
            byte c;
            while ((c = read()) != -1) {
                if (c == '\r')        continue;
                if (c == '\n')        break;
                lineBuf[ctr++] = c;
            }
            return new String(lineBuf, 0, ctr);
        }
        public String next() throws IOException {
            if (lineBuf == null)	lineBuf = new byte[MAX_LINE_SIZE];
            int ctr = 0;
            byte c = read();
            while (c <= ' ')  	c = read();
            while (c > ' ') {
                lineBuf[ctr++] = c;
                c = read();
            }
            return new String(lineBuf, 0, ctr);
        }
        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')   c = read();
            boolean neg = (c == '-');
            if (neg)           c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');

            if (neg)           return -ret;
            return ret;
        }
        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')    c = read();
            boolean neg = (c == '-');
            if (neg)            c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)            return -ret;
            return ret;
        }
        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)  	c = read();
            do {
                ret = ret * 10 + c - '0';
            }
            while ((c = read()) >= '0' && c <= '9');
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
            if (neg)     return -ret;
            return ret;
        }
        private void fillBuffer() throws IOException {
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }
        private byte read() throws IOException {
            if (bufferPointer == bytesRead)     fillBuffer();
            return buffer[bufferPointer++];
        }
        public void close() throws IOException {
            if (din == null) 	   return;
            din.close();
        }
    }
}