#define wiwihorz
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma loop-opt(on)
#define rep(i, a, b) for(int i = a; i <= b; i ++)
#define rrep(i, a, b) for(int i = b; i >= a; i--)
#define all(x) x.begin(), x.end()
using namespace std;
#define pii pair<int, int>
namespace solver {
int n;
vector<int> a, b, vis;
vector<pii> ans;
void init_(int _n) {
n = _n;
a.assign(n + 1, 0);
b.assign(n + 1, 0);
ans.clear();
}
void sswap(int x, int y) {
ans.push_back({x, y});
swap(a[x], a[y]);
swap(a[n - x + 1], a[n - y + 1]);
}
int get(int x) {
return x > n / 2 ? n - x + 1: x;
}
void solve() {
int cnt = 0;
rep(i, 1, n / 2) {
if(a[i] + a[n - i + 1] != n + 1) {
cout << "-1\n";
return;
}
if(a[i] > n / 2) cnt ++;
}
if(cnt & 1) {
cout << "-1\n";
return;
}
vector<int> temp;
vis.assign(n + 1, 0);
int pre = 0;
rep(i, 1, n / 2) if(!vis[i]) {
temp.clear(), vis[i] = 1;
if(a[i] > n / 2) temp.push_back(i);
for(int j = get(a[i]); j != i; j = get(a[j])) {
if(a[j] > n / 2) temp.push_back(j);
vis[j] = 1;
}
if(temp.size() % 2 == 1) {
if(pre) sswap(pre, n - temp.back() + 1), pre = 0;
else pre = temp.back();
temp.pop_back();
}
for(int j = 0; j < temp.size(); j += 2)
sswap(temp[j], n - temp[j + 1] + 1);
}
vis.assign(n + 1, 0);
rep(i, 1, n / 2) if(!vis[i]) {
temp.clear(), vis[i] = 1;
temp.push_back(i);
for(int j = get(a[i]); j != i; j = get(a[j])) {
temp.push_back(j), vis[j] = 1;
}
for(int j = 1; j < temp.size(); j ++)
sswap(temp[j], temp[j - 1]);
}
cout << ans.size() << " " << ans.size() << "\n";
for(auto i : ans) cout << i.first << " " << i.second << "\n";
}
};
using namespace solver;
signed main() {
ios::sync_with_stdio(false), cin.tie(0);
int t; cin >> t;
while(t--) {
int n; cin >> n;
init_(n);
rep(i, 1, n) cin >> a[i];
solve();
}
return 0;
}
