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.math.*;
import java.io.*;
import java.util.*;
import java.awt.*;

public class Main implements Runnable {
    @Override
    public void run() {
        try {
            new Solver().solve();
            System.exit(0);
        } catch (Exception | Error e) {
            e.printStackTrace();
            System.exit(1);
        }
    }

    public static void main(String[] args) {
        //new Thread(null, new Main(), "Solver", 1l << 25).start();
        new Main().run();
    }
}

class SegmentTree {
    private int N;
    private int[] tree, lazy;

    public SegmentTree(int[] ar) {
        N = 1;
        while (N < ar.length) N <<= 1;
        tree = new int[N * 2 - 1];
        lazy = new int[N * 2 - 1];

        for (int i = 0; i < ar.length; ++i) tree[i + N - 1] = ar[i];
        for (int i = N - 2; i >= 0; --i) tree[i] = tree[i * 2 + 1] + tree[i * 2 + 2];
    }

    public void pushDown(int i, int l, int r) {
        tree[i] += lazy[i] * (r - l + 1);
        if (i * 2 + 1 < tree.length) {
            lazy[i * 2 + 1] += lazy[i];
            lazy[i * 2 + 2] += lazy[i];
        }
        lazy[i] = 0;
    }

    public void rangeUpdate(int l, int r, int val) {
        update(0, 0, N - 1, l, r, val);
    }

    public int rangeQuery(int l, int r, int key) {
        return query(0, 0, N - 1, l, r, key);
    }


    private void update(int i, int l, int r, int ql, int qr, int val) {
        pushDown(i, l, r);
        int mid = l + r >> 1, i2 = i << 1;
        if (l > qr || r < ql) return;
        else if (l >= ql && r <= qr) {
            lazy[i] += val;
            pushDown(i, l, r);
        } else {
            update(i2 + 1, l, mid, ql, qr, val);
            update(i2 + 2, mid + 1, r, ql, qr, val);

            // Rebuild tree[i] if necessary
            tree[i] = tree[i2 + 1] + tree[i2 + 2];
        }
    }

    private int query(int i, int l, int r, int ql, int qr, int key) {
        pushDown(i, l, r);
        int mid = l + r >> 1, i2 = i << 1;
        if (l > qr || r < ql) return 0;
        else if (l >= ql && r <= qr) return tree[i];
        else {
            return query(i2 + 1, l, mid, ql, qr, key)
                    + query(i2 + 2, mid + 1, r, ql, qr, key);
        }
    }
}


class Solver {
    final Helper hp;
    final int MAXN = 1000_006;
    final long MOD = (long) 1e9 + 7;

    final Timer timer;
    final TimerTask task;

    Solver() {
        hp = new Helper(MOD, MAXN);
        hp.initIO(System.in, System.out);

        timer = new Timer();
        task = new TimerTask() {
            @Override
            public void run() {
                try {
                    hp.flush();
                    System.exit(0);
                } catch (Exception e) {
                }
            }
        };
        //timer.schedule(task, 4700);
    }


    void solve() throws Exception {
        int i, j, k;
        boolean testCases = true;
        Random rnd = new Random();

        int tc = testCases ? hp.nextInt() : 1;
        for (int tce = 1; tce <= tc; tce++) {
            int N = hp.nextInt(), K = hp.nextInt();
            int[] A = hp.getIntArray(N);

            SegmentTree cost1 = new SegmentTree(new int[2 * K + 3]);
            SegmentTree cost2 = new SegmentTree(new int[2 * K + 3]);

            for (i = 0; i < N / 2; ++i) {
                int a = A[i], b = A[N - 1 - i];
                int min = Math.min(a, b) + 1, max = Math.max(a, b) + K;

                cost1.rangeUpdate(min, a + b - 1, +1);
                cost1.rangeUpdate(a + b + 1, max, +1);

                cost2.rangeUpdate(2, min - 1, +1);
                cost2.rangeUpdate(max + 1, 2 * K, +1);
            }

            int minCost = N;
            for (i = 2; i <= 2 * K; ++i) {
                minCost = Math.min(minCost,
                        cost1.rangeQuery(i, i, -7) + 2 * cost2.rangeQuery(i, i, -7));
            }
            hp.println(minCost);
        }

        timer.cancel();
        hp.flush();
    }

}

class Helper {
    final long MOD;
    final int MAXN;
    final Random rnd;

    public Helper(long mod, int maxn) {
        MOD = mod;
        MAXN = maxn;
        rnd = new Random();
    }


    public static int[] sieve;
    public static ArrayList<Integer> primes;

    public void setSieve() {
        primes = new ArrayList<>();
        sieve = new int[MAXN];
        int i, j;
        for (i = 2; i < MAXN; ++i)
            if (sieve[i] == 0) {
                primes.add(i);
                for (j = i; j < MAXN; j += i) {
                    sieve[j] = i;
                }
            }
    }


    public static long[] factorial;

    public void setFactorial() {
        factorial = new long[MAXN];
        factorial[0] = 1;
        for (int i = 1; i < MAXN; ++i) factorial[i] = factorial[i - 1] * i % MOD;
    }

    public long getFactorial(int n) {
        if (factorial == null) setFactorial();
        return factorial[n];
    }

    public long ncr(int n, int r) {
        if (r > n) return 0;
        if (factorial == null) setFactorial();
        long numerator = factorial[n];
        long denominator = factorial[r] * factorial[n - r] % MOD;
        return numerator * pow(denominator, MOD - 2, MOD) % MOD;
    }


    public long[] getLongArray(int size) throws Exception {
        long[] ar = new long[size];
        for (int i = 0; i < size; ++i) ar[i] = nextLong();
        return ar;
    }

    public int[] getIntArray(int size) throws Exception {
        int[] ar = new int[size];
        for (int i = 0; i < size; ++i) ar[i] = nextInt();
        return ar;
    }

    public String[] getStringArray(int size) throws Exception {
        String[] ar = new String[size];
        for (int i = 0; i < size; ++i) ar[i] = next();
        return ar;
    }

    public String joinElements(long... ar) {
        StringBuilder sb = new StringBuilder();
        for (long itr : ar) sb.append(itr).append(" ");
        return sb.toString().trim();
    }


    public String joinElements(int... ar) {
        StringBuilder sb = new StringBuilder();
        for (int itr : ar) sb.append(itr).append(" ");
        return sb.toString().trim();
    }

    public String joinElements(String... ar) {
        StringBuilder sb = new StringBuilder();
        for (String itr : ar) sb.append(itr).append(" ");
        return sb.toString().trim();
    }

    public String joinElements(Object... ar) {
        StringBuilder sb = new StringBuilder();
        for (Object itr : ar) sb.append(itr).append(" ");
        return sb.toString().trim();
    }


    public long gcd(long a, long b) {
        return b == 0 ? a : gcd(b, a % b);
    }

    public int gcd(int a, int b) {
        return b == 0 ? a : gcd(b, a % b);
    }


    public long max(long... ar) {
        long ret = ar[0];
        for (long itr : ar) ret = Math.max(ret, itr);
        return ret;
    }

    public int max(int... ar) {
        int ret = ar[0];
        for (int itr : ar) ret = Math.max(ret, itr);
        return ret;
    }

    public long min(long... ar) {
        long ret = ar[0];
        for (long itr : ar) ret = Math.min(ret, itr);
        return ret;
    }

    public int min(int... ar) {
        int ret = ar[0];
        for (int itr : ar) ret = Math.min(ret, itr);
        return ret;
    }


    public long sum(long... ar) {
        long sum = 0;
        for (long itr : ar) sum += itr;
        return sum;
    }

    public long sum(int... ar) {
        long sum = 0;
        for (int itr : ar) sum += itr;
        return sum;
    }

    public void shuffle(Integer[] ar) {
        int r;
        for (int i = 0; i < ar.length; ++i) {
            r = rnd.nextInt(ar.length);
            if (r != i) {
                ar[i] ^= ar[r];
                ar[r] ^= ar[i];
                ar[i] ^= ar[r];
            }
        }
    }

    public void shuffle(long[] ar) {
        int r;
        for (int i = 0; i < ar.length; ++i) {
            r = rnd.nextInt(ar.length);
            if (r != i) {
                ar[i] ^= ar[r];
                ar[r] ^= ar[i];
                ar[i] ^= ar[r];
            }
        }
    }

    public void reverse(int[] ar) {
        int r;
        for (int i = 0; i < ar.length; ++i) {
            r = ar.length - 1 - i;
            if (r > i) {
                ar[i] ^= ar[r];
                ar[r] ^= ar[i];
                ar[i] ^= ar[r];
            }
        }
    }

    public void reverse(long[] ar) {
        int r;
        for (int i = 0; i < ar.length; ++i) {
            r = ar.length - 1 - i;
            if (r > i) {
                ar[i] ^= ar[r];
                ar[r] ^= ar[i];
                ar[i] ^= ar[r];
            }
        }
    }

    public long pow(long base, long exp, long MOD) {
        base %= MOD;
        long ret = 1;
        while (exp > 0) {
            if ((exp & 1) == 1) ret = ret * base % MOD;
            base = base * base % MOD;
            exp >>= 1;
        }
        return ret;
    }


    static final int BUFSIZE = 1 << 20;
    static byte[] buf;
    static int index, total;
    static InputStream in;
    static BufferedWriter bw;


    public void initIO(InputStream is, OutputStream os) {
        try {
            in = is;
            bw = new BufferedWriter(new OutputStreamWriter(os));
            buf = new byte[BUFSIZE];
        } catch (Exception e) {
        }
    }

    public void initIO(String inputFile, String outputFile) {
        try {
            in = new FileInputStream(inputFile);
            bw = new BufferedWriter(new OutputStreamWriter(
                    new FileOutputStream(outputFile)));
            buf = new byte[BUFSIZE];
        } catch (Exception e) {
        }
    }

    private int scan() throws Exception {
        if (index >= total) {
            index = 0;
            total = in.read(buf);
            if (total <= 0)
                return -1;
        }
        return buf[index++];
    }

    public String next() throws Exception {
        int c;
        for (c = scan(); c <= 32; c = scan()) ;
        StringBuilder sb = new StringBuilder();
        for (; c > 32; c = scan())
            sb.append((char) c);
        return sb.toString();
    }

    public int nextInt() throws Exception {
        int c, val = 0;
        for (c = scan(); c <= 32; c = scan()) ;
        boolean neg = c == '-';
        if (c == '-' || c == '+')
            c = scan();
        for (; c >= '0' && c <= '9'; c = scan())
            val = (val << 3) + (val << 1) + (c & 15);
        return neg ? -val : val;
    }

    public long nextLong() throws Exception {
        int c;
        long val = 0;
        for (c = scan(); c <= 32; c = scan()) ;
        boolean neg = c == '-';
        if (c == '-' || c == '+')
            c = scan();
        for (; c >= '0' && c <= '9'; c = scan())
            val = (val << 3) + (val << 1) + (c & 15);
        return neg ? -val : val;
    }

    public void print(Object a) throws Exception {
        bw.write(a.toString());
    }

    public void printsp(Object a) throws Exception {
        print(a);
        print(" ");
    }

    public void println() throws Exception {
        bw.write("\n");
    }

    public void println(Object a) throws Exception {
        print(a);
        println();
    }

    public void flush() throws Exception {
        bw.flush();
    }
}