#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <climits>
#include <cstring>
#include <cassert>


using namespace std;
#define SZ(x) (int)(x.size())
#define REP(i, n) for(int i=0;i<n;++i)
#define FOR(i, a, b) for(int i=a;i<b;++i)
#define RREP(i, n) for(int i=n-1;i>=0;--i)
#define RFOR(i, a, b) for(int i=b-1;i>=a;--i)

#define all(x) begin(x),end(x)
#define dump(x) cerr<<#x<<" = "<<(x)<<endl
#define debug(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<< endl;

using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using P = pair<int, int>;
const double eps = 1e-8;
const ll MOD = 1000000007;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;

template<class T>
bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmin(T &a, const T &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}


template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> p) {
    os << p.first << ":" << p.second;
    return os;
}

template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
    os << "[";
    REP(i, SZ(v)) {
        if (i) os << ", ";
        os << v[i];
    }
    return os << "]";
}

template<class T1, class T2>
ostream &operator<<(ostream &os, const map<T1, T2> &mp) {
    os << "[";
    for (auto it = mp.begin(); it != mp.end(); ++it) {
        if (it != mp.begin()) {
            os << ", ";
        }
        os << *it;
    }
    return os << "]";
}

// edit

void add_edge(vector<vector<int>> &G, int from, int to) {
    G[from].push_back(to);
    G[to].push_back(from);
}

int add_node(vector<vector<int>> &G, vector<int> &deg, int v, int d) {
    int sz = G.size();
    G.push_back(vector<int>());
    deg.push_back(d);
    if (v == -1) {
    } else {
        G[v].push_back(sz);
        G[sz].push_back(v);
    }
    return sz;
}

void solve() {
    vector<int> inp;
    while (true) {
        int tmp;
        cin >> tmp;
        if (tmp == 0) break;
        inp.push_back(tmp);
    }

    vector<vector<int>> G;
    vector<int> path;
    vector<int> deg;

    int v = -1; // current state
//    path.push_back(0);
//    G.push_back(vector<int>(0));

    for (auto e : inp) {
        while (v != -1 && G[v].size() == deg[v]) {
            path.pop_back();
            v = path.back();
        }
        if (e > 0) {
            v = add_node(G, deg, v, e);
            path.push_back(v);
        } else {
            int from = v;
            int to = *(path.end() + e - 1);
            add_edge(G, from, to);
        }
    }

    for (int i = 0; i < G.size(); ++i) {
        cout << i + 1 << " ";
        sort(all(G[i]));
//        for (auto e : G[i]) {
        for (int j = 0; j < G[i].size(); ++j) {
            int e = G[i][j];
            cout << e + 1;
            if (j + 1 == G[i].size()) {
            } else {
                cout << " ";
            }
        }
        cout << endl;
    }
}


int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
//    std::ifstream in("input.txt");
//    std::cin.rdbuf(in.rdbuf());

    int n;
    cin >> n;
    REP(i, n)solve();


    return 0;
}

