#include <bits/stdc++.h>
using namespace std;
const int N = 2e5+1;
#define pii pair<int, int>
int p[N], x[N], n;
vector<pii> v;
void swp(int i, int j) {
v.push_back({i, j});
swap(p[i], p[j]), swap(x[p[i]], x[p[j]]);
swap(p[n-i+1], p[n-j+1]), swap(x[p[n-i+1]], x[p[n-j+1]]);
}
void solve() {
cin>>n; v.clear();
for (int i=1; i<=n; ++i) {
cin>>p[i];
x[p[i]]=i;
}
bool ok=true;
for (int i=1; i<=n/2; ++i) {
if (p[n-i+1] != n-p[i]+1) ok=false;
}
int c=0;
for (int i=1; i<=n/2; ++i) {
if (p[i] > n/2) ++c;
}
if (!ok || c%2) {
cout<<-1<<"\n";
return;
}
stack<int> s;
for (int i=1; i<=n/2; ++i) {
if (p[i] <= n/2) continue;
int r=n-p[i]+1;
if (x[r] > n/2 && x[r] != n-i+1) swp(i, x[r]);
else if (x[i] > n/2 && x[i] != n-i+1) swp(i, x[i]);
else if (p[r] > n/2 && p[r] != x[r] && x[r] != n-p[r]+1) swp(p[r], x[r]);
}
for (int i=1; i<=n/2; ++i) {
if (p[i] > n/2) s.push(i);
}
assert(s.size()%2 == 0);
while (!s.empty()) {
int a=s.top(); s.pop();
int b=s.top(); s.pop();
swp(a, n-b+1);
}
for (int i=1; i<=n/2; ++i) {
while (p[i] != i) swp(i, p[i]);
}
cout<<v.size()<<" "<<v.size()<<"\n";
for (auto u : v) cout<<u.first<<" "<<u.second<<"\n";
}
int main() {
int t; cin>>t;
while (t--) solve();
}
