#include <iostream>
#include <cassert>
#include <vector>
using namespace std;
vector<pair<int, int>> sort_ops(vector<int> p) {
int n = p.size();
vector<int> rp(n);
for (int i = 0; i < n; ++i)
rp[p[i]] = i;
vector<pair<int, int>> ans;
for (int t = 0; t < n; ++t) {
if (p[t] == t)
continue;
int i = rp[t];
ans.push_back({t, i});
swap(p[i], p[t]);
rp[p[t]] = t;
rp[p[i]] = i;
}
return ans;
}
void solve() {
int n;
cin >> n;
vector<int> p(n);
for (int i = 0; i < n; ++i)
cin >> p[i], --p[i];
for (int i = 0; i < n; ++i) if (p[i] + p[n - i - 1] != n - 1) {
cout << "-1\n";
return;
}
int e1 = 0;
for (int i = 0; i < n / 2; ++i)
e1 += p[i] >= n / 2;
if (e1 % 2) {
cout << "-1\n";
return;
}
vector<int> rp(n);
for (int i = 0; i < n; ++i)
rp[p[i]] = i;
vector<pair<int, int>> ans;
for (int t = 0; t < n / 2; ++t) {
if (p[t] == t || p[t] >= n / 2)
continue;
int i = rp[t];
ans.push_back({t, i});
//cout << "! " << t << ' ' << i << ": " << p[t] << ' ' << p[i] << endl;
swap(p[i], p[t]);
swap(p[n - 1 - i], p[n - 1 - t]);
rp[p[t]] = t;
rp[p[i]] = i;
}
//for (int i = 0; i < n; ++i)
//cout << p[i] << ' ';
//cout << endl;
vector<int> prp(n / 2);
for (int i = 0; i < n / 2; ++i) {
if (p[i] == i)
prp[i] = i;
else {
assert(p[i] >= n / 2);
prp[i] = n - 1 - p[i];
}
}
vector<int> singles;
for (int i = 0; i < n / 2; ++i) {
if (p[i] == i)
continue;
if (prp[i] == i) {
singles.push_back(i);
continue;
}
int j = i;
vector<int> a;
do {
a.push_back(j);
j = prp[j];
} while (j != i);
//cout << i << ": ";
//for (auto x : a)
//cout << x << ' ';
//cout << endl;
for (size_t t = 1; t < a.size(); ++t) {
swap(prp[a[0]], prp[a[t]]);
swap(p[a[0]], p[n - 1 - a[t]]);
swap(p[a[t]], p[n - 1 - a[0]]);
ans.push_back({a[0], n - 1 - a[t]});
}
}
while (singles.size()) {
int i = singles.back();
singles.pop_back();
int j = singles.back();
singles.pop_back();
ans.push_back({i, n - 1 - j});
ans.push_back({i, j});
//cout << "{ " << i << ' ' << j << " }" << endl;
}
//if (e1 == 0) {
//vector<int> p0(n / 2);
//for (int i = 0; i < n / 2; ++i)
//p0[i] = p[i];
cout << ans.size() << ' ' << ans.size() << '\n';
for (auto x : ans)
cout << x.first + 1 << ' ' << x.second + 1 << '\n';
//return;
//}
//cout << "1 1\n";
//cout << "1 2\n";
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int t;
cin >> t;
while (t--) {
solve();
}
}
