#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)
#define Inf 1000000001

int main(){
	
	
	
	int _t;
	cin>>_t;
	
	rep(_,_t){
		
		int n;
		cin>>n;
		
		vector<int> p(n);
		rep(i,n){
			cin>>p[i];
			p[i]--;
		}
		bool f = true;
		vector<int> a;
		rep(i,n){
			int ind = 0;
			rep(j,n){
				if(p[j]==i){
					ind = j;
					break;
				}
			}
			while(ind!=i){
				if(p[ind-1] == ind-1){
					f = false;
					break;
				}
				int cur = ind-1;
				bool F = false;
				while(true){
					if(cur==-1 || p[cur] < i){
						F = true;
						break;
					}
					if(cur+1 == p[cur])cur--;
					else break;
				}
				//cout<<cur<<endl;
				if(F){
					while(p[i] != i){
						a.push_back(ind-1);
						swap(p[ind],p[ind-1]);
						ind--;
					}
				}
				else{
					while(cur!=ind){
						a.push_back(cur);
						swap(p[cur],p[cur+1]);
						cur++;
					}
					ind--;
				}
			}
			if(!f)break;
		}
		if(!f){
			cout<<-1<<endl;
		}
		else{
			/*
			rep(i,n)cout<<p[i]<<',';
			cout<<endl;
			*/
			assert(a.size()<=n*n);
			cout<<a.size()<<endl;
			rep(i,a.size()){
				if(i!=0)cout<<' ';
				cout<<a[i]+1;
			}
			cout<<endl;
		}
		
	}
	
	return 0;
}