#include <iostream>
#include <set>
#include <vector>

using namespace std;

main()
{
	int loop;
	cin >> loop;
	while (loop--){
		int r;
		vector<multiset<int> > graph(101);
		vector<int> edge(101);
		edge[0] = 1;
		vector<int> path;
		path.push_back(0);
		int index = 1;
		while (cin >> r && r){
			if (r > 0){
				while (edge[path.back()] == 0){
					path.pop_back();
				}
				graph[path.back()].insert(index);
				graph[index].insert(path.back());
				--edge[path.back()];
				edge[index] = r - 1;
				path.push_back(index);
				++index;
				while (edge[path.back()] == 0){
					path.pop_back();
				}
			} else {
				while (edge[path.back()] == 0){
					path.pop_back();
				}
				graph[path.back()].insert(path[path.size() + r - 1]);
				graph[path[path.size() + r - 1]].insert(path.back());
				--edge[path.back()];
				--edge[path[path.size() + r - 1]];
				while (edge[path.back()] == 0){
					path.pop_back();
				}
			}
		}
		index = 1;
		while (!graph[index].empty()){
			cout << index;
			for (multiset<int>::iterator it = graph[index].begin(); it != graph[index].end(); ++it){
				if (*it == 0){
					continue;
				}
				cout << " " << *it;
			}
			cout << endl;
			++index;
		}
	}
}