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.util.*;
import java.io.*;
public class CodeforcesNewbie_Problem_D
{
	// Problem uses Prefix sum method.
    static InputReader in=new InputReader(System.in);
    static OutputWriter out=new OutputWriter(System.out);    
    static StringBuilder sb=new StringBuilder();
    static long MOD = (long)(1e9+7);
    // Main Class Starts Here        
    public static void main(String args[])throws IOException
    {
    	// Write your code.
    	int t = in();
    	while(t-->0) {
    		int n = in();
    		int k = in();
    		int a[] = an(n);
    		
    		int sum[] = new int[n/2];
    
    		for(int i = 0; i<n/2;i++) {
    			sum[i] = a[i] + a[n-i-1];
    		}
    		
    		// range of same value will be  [2 , 2k]
    		// for each value we need to see for which we 
    		// will need minimum changes. That will be
    		// our answer.
    		// that will O(n/2 * k) TLE.
    		// So use prefix sum method.
    		
    		// three cases arise for each pair of a[i],a[n-i-1]
    		// by taking valid y for 2 <= y <= 2k.
    		// 1.)  0 changes to make in pair.
    		// 2.)  1 change to make.
    		// 3.)  2 changes to make.
    		
    		// we are interested in 0 and 1 , because when we find these two.
    		// 3rd case can be found out by using : (n/2 - 1st case - 2nd case).
    		
    		// for 1 change in a pair the range will be min(a[i],a[n-i-1]) + 1
    		// to max(a[i],a[n-i-1] + k. Now we have ranges, use prefix method.
    		
    		int ar[] = new int[2*k + 2];
    		for(int i=0;i<n/2;i++) {
    			int min = min(a[i],a[n-i-1]);
    			int max = max(a[i],a[n-i-1]);
    			// range = min+1 , max+k,
    			ar[min+1]++;
    			ar[max+k+1]--; 
    		}
    		// prefix sum.
    		for(int i=1;i<ar.length;i++) {
    			ar[i] += ar[i-1];
    		}
    		// calculate the 1st case count 
    		int zero[] = new int[2*k + 2];
    		for(int i=0;i<n/2;i++) {
    			zero[sum[i]]++;
    		}
    		int min = Integer.MAX_VALUE;    		
    		for(int i=2; i<=(2*k);i++) {
    			int val = (ar[i] - zero[i]) + 2 * ((n/2) - ar[i]);
    			min = min(min,val);
    		}
    		app(min+"\n");
    	}    	    	
    	out.printLine(sb);
    	out.close();
    }
           
    public static long rev(long n) {
    	if(n<10L)
    		return n;
    	long rev = 0L;
    	while(n != 0L) {
    		long a = n % 10L;
    		rev = a + rev*10L;
    		n /= 10L;
    	}
    	return rev;
    }
    
    public static int min(int x,int y) {
    	return Math.min(x, y);
    }
    
    public static int max(int x,int y) {
    	return Math.max(x, y);
    }
    
    public static long pow(long a,long b) {
    	if(b==0)
    		return 1L;
    	if(b==1)
    		return a % MOD;
    	long f = a * a;
    	if(f > MOD)
    		f %= MOD;
    	long val = pow(f, b/2) % MOD;
    	if(b % 2 == 0)
    		return val;
    	else {
    		long temp = val * (a % MOD);
    		if(temp > MOD)
    			temp = temp % MOD;
    		return temp;
    	}
    }
    
    public static int gcd(int a,int b) {
    	if(b==0)
    		return a;
    	return gcd(b, a%b);
    }
    
    public static int[] an(int n) {
    	int ar[]=new int[n];
    	for(int i=0;i<n;i++)
    		ar[i]=in();
    	return ar;
    }
    
    public static int in() {
    	return in.readInt();
    }
    
    public static long lin() {
    	return in.readLong();
    }    
    
    public static String sn() {
    	return in.readString();
    }
    
    public static void prln(Object o) {    	
    	out.printLine(o);
    }
    
    public static void prn(Object o) {    	
    	out.print(o);
    }
    
    public static int getMax(int a[]) {
    	int n = a.length;
    	int max = a[0];
    	for(int i=1; i < n; i++) {
    		max = Math.max(max, a[i]);
    	}
    	return max;
    }
    
    public static int getMin(int a[]) {
    	int n = a.length;
    	int min = a[0];
    	for(int i=1; i < n; i++) {
    		min = Math.min(min, a[i]);
    	}
    	return min;
    }
    
    public static void display(int a[]) {
    	out.printLine(Arrays.toString(a));
    }    
    
    public static HashMap<Integer,Integer> hm(int a[]){
    	HashMap<Integer,Integer> map=new HashMap<>();
    	for(int i=0; i < a.length;i++) {
    		int keep = (int)map.getOrDefault(a[i],0);
    		map.put(a[i],++keep);
    	}
    	return map;
    }
    
    public static void app(Object o) {
    	sb.append(o);
    }
    
    public static long calcManhattanDist(int x1,int y1,int x2,int y2) {
    	long xa = Math.abs(x1-x2);
    	long ya = Math.abs(y1-y2);
    	return (xa+ya);
    }
    
    static class Point
    {
    	int x;
    	int y;
    	String dir;
    	public Point(int x,int y,String dir) {
    		this.x=x;
    		this.y=y;
    		this.dir=dir;
    	}
    }    
    
    
    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1)
                throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int readInt() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public long readLong() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public String readString() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return readString();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
        }
    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object...objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0)
                    writer.print(' ');
                writer.print(objects[i]);
            }
        }

        public void printLine(Object...objects) {
            print(objects);
            writer.println();
        }

        public void close() {
            writer.close();
        }
    } 
}