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 PYTHON):

Solution:
from collections import Counter, defaultdict, deque
import bisect
from sys import stdin, stdout
from itertools import repeat
import math
import random

# sys.stdin = open('input')

def inp():
    return map(int, raw_input().split())

def inst():
    return raw_input().strip()


def my_main():
        t = inp()[0]
        for _ in range(t):
            n, k = inp()
            da = inp()
            mp = defaultdict(int)
            dmin = []
            dmax = []
            for i in range(n/2):
                a, b = da[i], da[n-i-1]
                mp[a+b] += 1
                dmin.append(min(a, b)+1)
                dmax.append(max(a, b)+k)
            dmin.sort()
            dmax.sort()
            ans = n/2
            n/=2
            for key, v in mp.iteritems():
                left = bisect.bisect_left(dmax, key)
                right = n - bisect.bisect_right(dmin, key)
                ans = min(ans, (left+right)*2+n-left-right-v)
            print ans









my_main()