// yes, i cat-ed "mkinitcpio.conf" file
// c: computer
// a: aided
// t: translation
#include <functional>
#include <iostream>
#include <sys/select.h>
#include <vector>
#include <algorithm>
using namespace std;
int main () {
ios::sync_with_stdio (false);
cin.tie (0);
cout.tie (0);
int t = 0;
cin >> t;
while (t--)
[]()->void {
int N = 0;
cin >> N;
vector <int> v (N + 1);
for (int i = 1; i <= N; i++)
cin >> v[i];
for (int i = 1; i <= N; i++)
if (v[i] + v[N - i + 1] != N + 1) {
cout << -1 << '\n';
return;
}
vector <bool> bad (N + 1);
for (int i = 1; i <= N; i++)
if (v[i] > N / 2) {
v[i] = N - v[i] + 1;
bad[i] = 1;
}
vector <pair <int, int> > movs;
int cnt_bad = 0;
int join = -1;
vector <bool> been (N + 1);
function <void(int)> dfs = [&](int p) {
been[p] = 1;
if (bad[p]) {
cnt_bad++;
join = p;
}
if (!been[v[p]])
dfs (v[p]);
};
vector <int> odd_cnt;
int ans = 0;
for (int i = 1; i <= N / 2; i++)
if (!been[i]) {
cnt_bad = 0, join = -1;
dfs (i);
if (cnt_bad % 2 == 1)
odd_cnt.emplace_back (join);
}
if (odd_cnt.size() % 2 == 1) {
cout << -1 << '\n';
return;
}
for (int i = 0; i < odd_cnt.size(); i += 2) {
movs.emplace_back (odd_cnt[i], N - odd_cnt[i + 1] + 1);
bad[odd_cnt[i]] = 0;
bad[odd_cnt[i + 1]] = 0;
swap (v[odd_cnt[i]], v[odd_cnt[i + 1]]);
}
vector <bool> fixed (N + 1);
for (int i = 1; i <= N / 2; i++)
if (!fixed[i]) {
while (v[i] != i) {
fixed[v[i]] = 1;
movs.emplace_back (i, v[i]);
v[i] = v[v[i]];
}
}
cout << movs.size() << ' ' << movs.size() << '\n';
for (auto [a, b] : movs)
cout << a << ' ' << b << '\n';
}();
}
