#ifdef LOCAL
#include <iostream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <random>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#else
#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
#define cerr if (false) cerr
#define endl '\n'
#endif
#define fi first
#define se second
#define sz(a) ((int)(a).size())
#define all(a) (a).begin(), (a).end()
#define lsb(x) (x & (-x))
#define bit(mask, i) (((mask) >> (i)) & 1)
#define popcount(x) __builtin_popcount(x)
#define YES cout << "YES" << endl
#define NO cout << "NO" << endl
using namespace std;
template <typename T>
bool ckmax(T &a, T b) { return a < b ? a = b, true : false; }
template <typename T>
bool ckmin(T &a, T b) { return a > b ? a = b, true : false; }
using ll = long long;
using pii = pair<int, int>;
const int NMAX = 3e6+5;
int n;
int a[NMAX];
int pos[NMAX];
vector<pii> ans;
vector<pii> bad;
void read() {
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> a[i];
pos[a[i]] = i;
}
}
void my_swap(int i, int j) {
ans.push_back({ i, j });
swap(pos[a[i]], pos[a[j]]);
swap(a[i], a[j]);
swap(pos[a[n - i + 1]], pos[a[n - j + 1]]);
swap(a[n - i + 1], a[n - j + 1]);
}
void solve() {
ans.clear();
bad.clear();
for (int i = 1; i <= n / 2; i++) {
if (a[i] != i) {
if (a[i] == n - i + 1) {
bad.push_back({ i, n - i + 1 });
} else {
my_swap(i, pos[i]);
}
}
}
for (int i = 0; i + 1 < int(bad.size()); i += 2) {
my_swap(bad[i].fi, bad[i + 1].fi);
my_swap(bad[i].fi, bad[i + 1].se);
}
for (int i = 1; i <= n; i++) {
if (a[i] != i) {
cout << -1 << endl;
return;
}
}
cout << ans.size() << ' ' << ans.size() << endl;
for (auto &[ i, j ] : ans)
cout << i << ' ' << j << endl;
}
signed main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int t = 1;
cin >> t;
while (t--) {
read();
solve();
}
return 0;
}
