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:
for _ in range(int(input())):
  n,k=map(int,input().split())
  a=list(map(int,input().split()))
  li=[0]*(2*k)
  pref=[0]*(2*k)
  c=[]
  if n==2:
    print(0)
    continue
  for i in range(n//2):
    li[a[i]+a[-i-1]-1]+=1
  ##print(li)


  for i in range(n//2):
    x,y=a[i],a[-i-1]
    range_min=min(x,y)+1
    range_max=max(x,y)+k
    pref[range_min-1]+=1
    if range_max<=(2*k)-1:
      pref[range_max]-=1
  for i in range(1,len(pref)):
    pref[i]+=pref[i-1]
  ##print(pref)

  for  i in range(2*k):
    c.append(n-pref[i]-li[i])
  print(min(c))