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 i in range(t):
    n,k=list(map(int,input().split()))
    arr=list(map(int,input().split()))
    if n==2:
        print(0)
    else:
        count=[0]*(2*k)
        for j in range(n//2):
            count[arr[j]+arr[-j-1]-1]+=1
        pref=[0]*(2*k)
        for j in range(n//2):
            x1=arr[j]+1
            x2=arr[-j-1]+1
            y1=arr[j]+k
            y2=arr[-j-1]+k
            pref[min(x1,x2)-1]+=1
            if max(y1,y2)<(2*k):
                pref[max(y1,y2)]-=1
        for j in range(1,2*k):
            pref[j]+=pref[j-1]
        ans=n//2
        for j in range(1,2*k):
            temp=(pref[j]-count[j])+(2*((n//2)-pref[j]))
            ans=min(ans,temp)
        print(ans)