ICPC-B

/**
 *    author:  compounding
 *    created: 2024-11-16 18:33:28
 **/
#include <bits/stdc++.h>
using namespace std;
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
#define NeedForSpeed                  \
    ios_base::sync_with_stdio(false); \
    cin.tie(NULL);                    \
    cout.tie(NULL);
#define int long long
#define all(x) (x).begin(), (x).end()
typedef vector<int> vi;
typedef vector<bool> vb;
typedef vector<vi> vvi;
typedef vector<pair<int, int>> vpi;
#define f first
#define s second
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define endl "\n"
const int mod = 1000000007;
int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
void solve()
{
    int n, d, l;
    cin >> n >> d >> l;
    // edge cases
    if (n <= l)
    {
        cout << -1 << endl;
        return;
    }
    vector<pair<int, int>> edges;
    // straight line
    for (int i = 1; i <= d; i++)
    {
        edges.push_back({i, i + 1});
    }
    int mid = (d + 2) / 2;
    // all leaves in mid
    int leaves_left = l - 2;
    int curnode = d + 2;
    // leaves lagate hain
    queue<pair<int, int>> q;
    for (; curnode <= n && (leaves_left > 0); curnode++)
    {
        edges.push_back({mid, curnode});
        leaves_left--;
        q.push({curnode, 1});
    }
    // step 2
    if (curnode > n && leaves_left > 0)
    {
        cout << -1 << endl;
        return;
    }
    if (leaves_left == 0)
    {
        for (auto edge : edges)
        {
            cout << edge.first << " " << edge.second << endl;
        }
        return;
    }
    else
    {
        // leaves fullfilled, but not n (total number of nodes)
        int buffer = mid - 1;
        while (!q.empty())
        {
            auto [node, dist] = q.front();
            q.pop();
            if (dist + 1 <= buffer)
            {
                edges.push_back({node, curnode});
                q.push({curnode, dist + 1});
                curnode++;
            }
        }
        // as all nodes have not been used
        if (curnode <= n)
        {
            cout << -1 << endl;
            return;
        }
        else
        {
            for (auto edge : edges)
            {
                cout << edge.first << " " << edge.second << endl;
            }
            // cout << "geeks";
        }
    }
    return;
}

signed main()
{
    NeedForSpeed;
    int t = 1;
    cin >> t;
    while (t--)
    {
        solve();
    }
    return 0;
}