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:
t=int(input())
for _ in range(t):
    n,k=map(int,input().split(" "))
    arr=list(map(int,input().split(" ")))
    start,end=2,2*k
    ans=float('inf')
    pairs=n//2
    temp=[0]*(2*k+1)
    d={}
    for i in range(n//2):
        val=arr[i]+arr[n-i-1]
        if val not in d:
            d[val]=1
        else:
            d[val]+=1
    for i in range(n//2):
        mm=min(arr[i],arr[n-i-1])+1
        maxx=max(min(arr[i]+k,2*k),min(arr[n-i-1]+k,2*k))
        temp[mm]+=1
        if maxx+1<=2*k:
            temp[maxx+1]-=1
    for i in range(1,2*k+1):
        temp[i]+=temp[i-1]
    
    for num in range(start,end+1):
        zeros=ones=twos=0
        if num in d:
            zeros=d[num]
        ones=temp[num]-zeros
        twos=pairs-ones-zeros
        val=ones+(twos*2)
        ans=min(ans,val)
    print(ans)