#include <bits/stdc++.h>
using namespace std;
#define EmiliaMyWife ios::sync_with_stdio(0); cin.tie(0);
using ll = int64_t;
using ull = uint64_t;
using uint = uint32_t;
using ld = long double;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
const ll LINF = ll(2e18) + ll(1e15);
const double EPS = 1e-8;
static auto LamyIsCute = []() {
EmiliaMyWife
return 48763;
}();
signed main() {
int t;
cin >> t;
while(t--) {
int n;
cin >> n;
vector<int> arr(n);
for(int &a : arr)
cin >> a;
{
bool ok = 1;
int w = 0;
for(int i = 0; i < n / 2; i++) {
if(arr[i] + arr[n - i - 1] != n + 1)
ok = false;
w += arr[i] > n / 2;
}
if(!ok || w % 2) {
cout << "-1\n";
continue;
}
}
vector<int> owo(n / 2);
for(int i = 0; i < n / 2; i++)
owo[i] = (arr[i] > n / 2 ? -(n + 1 - arr[i]) : arr[i]);
vector<int> pos(n / 2 + 1);
vector<pair<int, int>> ans;
int tag = -1;
for(int i = 0; i < n / 2; i++) {
pos[abs(owo[i])] = i;
}
for(int i = 0; i < n / 2; i++) {
if(pos[i + 1] == i) {
if(owo[i] < 0) {
if(tag == -1)
tag = i;
else {
ans.push_back({i, tag});
ans.push_back({i, n - tag - 1});
owo[i] *= -1;
owo[tag] *= -1;
tag = -1;
}
}
}
else {
int g = pos[i + 1];
if(owo[g] < 0) {
ans.push_back({i, n - g - 1});
owo[g] *= -1;
owo[i] *= -1;
}
else {
ans.push_back({i, g});
}
swap(pos[i + 1], pos[abs(owo[i])]);
swap(owo[g], owo[i]);
}
}
cout << ans.size() << ' ' << ans.size() << '\n';
for(const auto &[a, b] : ans)
cout << a + 1 << ' ' << b + 1 << '\n';
}
}
