#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 p[MAXN+1];
bool need[MAXN+1];
int tmp, cnt;
vector <pii> ans;
void output(int N) {
cout << "\n";
for (int i = 1; i <= N; i++)
cout << a[i] << " \n"[i==N];
}
void solve(int N) {
for (int i = 1; i <= N; i++) {
if (a[i] != i) {
if (!need[i] && !need[p[i]]) {
ans.pb(pii(i, p[i]));
swap(a[n-i+1], a[n-p[i]+1]);
swap(p[a[n-i+1]], p[a[n-p[i]+1]]);
swap(a[i], a[p[i]]);
swap(p[a[i]], p[a[p[i]]]);
} else {
need[i] ^= 1, need[p[i]] ^= 1;
ans.pb(pii(i, n-p[i]+1));
swap(a[n-i+1], a[n-p[i]+1]);
swap(p[a[n-i+1]], p[a[n-p[i]+1]]);
swap(a[i], a[p[i]]);
swap(p[a[i]], p[a[p[i]]]);
}
}
}
cnt = 0;
for (int i = 1; i <= N; i++) {
if (need[i]) {
if (cnt % 2) {
ans.pb(pii(i, tmp));
ans.pb(pii(i, n-tmp+1));
}
cnt++;
tmp = 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;
for (int i = 1; i <= n; i++)
need[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]);
p[a[n-i+1]] = n-i+1;
p[a[i]] = i;
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";
}
}
}
