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 PYTHON3):

Solution:
from bisect import bisect_left as bl
from bisect import bisect_right as br
from heapq import heappush,heappop
import math
from collections import *
from functools import reduce,cmp_to_key
# import io, os
# input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline
import sys
input = sys.stdin.readline

M = mod = 998244353
def factors(n):return sorted(set(reduce(list.__add__, ([i, n//i] for i in range(1, int(n**0.5) + 1) if n % i == 0))))
def inv_mod(n):return pow(n, mod - 2, mod)

def li():return [int(i) for i in input().split()]
def st():return input()
def val():return int(input().rstrip('\n'))
def li2():return [i for i in input()]
def li3():return [int(i) for i in input()]


for _ in range(val()):
    n,k = li()
    l = li()
    cnt = Counter()
    mins = []
    maxs = []
    sums = []
    arr = [0]*(2*k + 5)
    for i in range(n//2):
        cnt[l[i] + l[n-i-1]] += 1
        a,b = max(l[i],l[n-i-1]),min(l[i],l[n-i-1])


        arr[b] += 1
        arr[a + k] -= 1


        maxs.append(a + k - b)
        mins.append(b + 1)

    mins.sort()
    maxs.sort()

    ans = n
    curr = arr[1]
    for i in range(2,2*k + 1,1):
        onecost = curr - cnt[i]
        twocost =  n//2 - curr
        ans = min(ans,onecost + twocost*2)
        curr += arr[i]
    print(ans)