// Author : hejinming2012
#include <bits/stdc++.h>
#define int long long
#define endl '\n'
#define dbg(x) cout << #x " = " << (x) << endl
#define quickio ios::sync_with_stdio(false);
#define quickin cin.tie(0);
#define quickout cout.tie(0);

using namespace std;
inline int read() {
	int now = 0, nev = 1; char c = getchar();
	while(c < '0' || c > '9') { if(c == '-') nev = -1; c = getchar(); }
	while(c >= '0' && c <= '9') { now = (now << 1) + (now << 3) + (c & 15); c = getchar(); }
	return now * nev;
}
void write(int x) {
	if(x < 0) putchar('-'), x = -x;
	if(x > 9) write(x / 10);
	putchar(x % 10 + '0');
}
struct node {
	vector <int> keys;
	vector <node*> ch;
	node() {}
};
class TTFT {
public :
	node *root;
	TTFT() : root(nullptr) {}
	void insert(int val) {
		if(root == nullptr) {
			root = new node();
			root -> keys.push_back(val);
			return ;
		}
		if(root -> keys.size() == 3) {
			node *nr = new node();
			nr -> ch.push_back(root);
			split(nr, root, 0);
			root = nr;
		}
		node *cur = root;
		while(1) {
			if(cur -> ch.empty()) {
				cur -> keys.push_back(val);
				sort(cur -> keys.begin(), cur -> keys.end());
				return ;
			}
			int chid = 0;
			while(chid < cur -> keys.size() && val > cur -> keys[chid]) chid++;
			node *child = cur -> ch[chid];
			if(child -> keys.size() == 3) {
				split(cur, child, chid);
				if(val > cur -> keys[chid]) chid++;
				child = cur -> ch[chid];
			}
			cur = child;
		}
	}
	void pre(vector < vector <int> > &res) {
		preOrder(root, res);
	}
private :
	void split(node *fa, node *ch, int chid) {
		int k2 = ch -> keys[1];
		node *l = new node();
		l -> keys.push_back(ch -> keys[0]);
		node *r = new node();
		r -> keys.push_back(ch -> keys[2]);
		if(!ch -> ch.empty()) {
			l -> ch.push_back(ch -> ch[0]);
			l -> ch.push_back(ch -> ch[1]);
			r -> ch.push_back(ch -> ch[2]);
			r -> ch.push_back(ch -> ch[3]);
		}
		fa -> keys.insert(fa -> keys.begin() + chid, k2);
		fa -> ch.erase(fa -> ch.begin() + chid);
		fa -> ch.insert(fa -> ch.begin() + chid, l);
		fa -> ch.insert(fa -> ch.begin() + chid + 1, r);
		delete ch;
	}
	void preOrder(node *nd, vector < vector <int> > &res) {
		if(nd == nullptr) return ;
		res.emplace_back(nd -> keys);
		for(auto ch : nd -> ch)
			preOrder(ch, res);
	}
};
signed main() {
	quickio
	quickin
    quickout
    int T = read();
	for(int _ = 1; _ <= T; _++) {
		int n = read();
		vector <int> val(n);
		for(int i = 0; i < n; i++)
			val[i] = read();
		TTFT tree;
		for(int i = 0; i < n; i++)
			tree.insert(val[i]);
		vector < vector <int> > Pre;
		tree.pre(Pre);
		printf("Case #%lld:\n", _);
		for(auto &ndk : Pre) {
			for(int i : ndk) write(i), putchar(' ');
			putchar(10);
		}
	}
	return 0;
}