C++ :

#include <bits/stdc++.h>
using namespace std;

int n, x;
int a[1009], cnt;

void dfs(int u) {
	if (!a[u]) return;
	
	dfs(u * 2);
	cout << a[u] << ' ';
	dfs(u * 2 + 1);
}

int main() {
	cin >> n;
	while (n --) {
		memset(a, 0, sizeof(a));
		cnt = 0;
		
		while (cin >> x && x != -1) {
			a[++ cnt] = x;
		}
		
		cout << int(log2(cnt)) + 1 << ' ';
		dfs(1);
		cout << endl;
	}

	return 0;
}