#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define pii pair<int,int>
#define ff first
#define ss second
using namespace std;
const int MAXN = 3000000;
int t, n;
int a[MAXN+1];
int c[MAXN+1];
int p[MAXN+1];
bool need[MAXN+1];
int tmp[MAXN+1];
int cnt;
vector <pii> ans;
void swp(int x, int y) {
swap(a[n-x+1], a[n-y+1]);
swap(p[a[n-x+1]], p[a[n-y+1]]);
swap(a[x], a[y]);
swap(p[a[x]], p[a[y]]);
}
void solve(int N) {
for (int i = 1; i <= N; i++) {
if (need[i]) {
int t = p[i];
while (!need[t] && t != i) t = p[t];
if (t == i) continue;
ans.pb(pii(i, n-t+1));
swp(i, t);
need[i] = need[t] = 0;
}
}
for (int i = 1; i <= N; i++) {
if (a[i] != i) {
swap(need[i], need[p[i]]);
ans.pb(pii(i, p[i]));
swp(i, p[i]);
}
}
cnt = 0;
for (int i = 1; i <= N; i++) {
if (need[i]) {
if (cnt % 2) {
ans.pb(pii(i, tmp[0]));
ans.pb(pii(i, n-tmp[0]+1));
need[i] = need[n-tmp[0]+1] = 0;
}
cnt++;
tmp[0] = n-i+1;
}
}
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0);
cin >> t;
while (t--) {
cin >> n;
bool tf = 1;
for (int i = 1; i <= n; i++) {
cin >> a[i];
p[a[i]] = i;
need[i] = 0;
c[i] = tmp[i] = 0;
}
ans.clear();
cnt = 0;
for (int i = 1; i <= n/2 && tf; i++) {
if (abs(a[n-i+1] + a[i]) != n+1) tf = 0;
if (a[i] > n/2) {
swap(a[n-i+1], a[i]);
swap(p[a[i]], p[a[n-i+1]]);
need[i] = 1;
cnt++;
}
}
if (cnt % 2) tf = 0;
if (!tf) {
cout << -1 << "\n";
} else {
solve(n/2);
cout << ans.size() << " " << ans.size() << "\n";
for (pii o : ans)
cout << o.ff << " " << o.ss << "\n";
}
}
}
