#include <stdio.h>
#include <string.h>

#include <queue>
#include <algorithm>

#define LOG(FMT...) fprintf(stderr, FMT)

#define fi first
#define se second
#define em emplace
#define eb emplace_back

using namespace std;

typedef long long LL;
constexpr int N = 4096;

int n;
int a[N];
vector<vector<int>> b[N];

bool inter(vector<int> &a, vector<int> &b) {
	for (int x : a) {
		for (int y : b) {
			if (x == y) {
				return true;
			}
		}
	}
	return false;
	int i = 0, j = 0;
	while (i < (int)a.size() && j < (int)b.size()) {
		if (a[i] == b[j]) {
			return true;
		}
		if (a[i] < b[j]) {
			++i;
		} else {
			++j;
		}
	}
	return false;
}

int merg(vector<vector<int>> &c, vector<vector<int>> &a, vector<vector<int>> &b) {
	vector<vector<int>> t;
	for (auto &u : a) {
		for (auto &v : b) {
			if (inter(u, v)) {
				continue;
			}
			t.eb();
			for (int x : u) {
				t.back().eb(x);
			}
			for (int y : v) {
				t.back().eb(y);
			}
			/* int i = 0, j = 0;
			while (i < (int)u.size() || j < (int)v.size()) {
				if (j == (int)v.size() || i < (int)u.size() && u[i] < v[j]) {
					t.back().eb(u[i++]);
				} else {
					t.back().eb(v[j++]);
				}
			} */
		}
	}
	if (t.size()) {
		c = t;
		return 0;
	}
	for (auto &u : a) {
		t.eb(u);
	}
	for (auto &v : b) {
		t.eb(v);
	}
	c = t;
	return 1;
}

int solve() {
	for (int x = 0; x < (1 << n); ++x) {
		b[x].clear();
		b[x].eb(vector<int>{0});
	}
	int sum = 0;
	for (int k = 1 << n; k > 1; ) {
		for (int x = 0; x < k; ++x) {
			int d = a[x + (k - 2)];
			for (auto &v : b[x]) {
				for (int &t : v) {
					t += d;
				}
			}
		}
		k >>= 1;
		int cnt = 0;
		for (int x = 0; x < k; ++x) {
			cnt += merg(b[x], b[2 * x], b[2 * x + 1]);
		}
		if (cnt >= 2) {
			return -1;
		}
		sum += cnt;
	}
	return sum;
}

int main() {
	int task;
	for (scanf("%d", &task); task--; ) {
		scanf("%d", &n);
		for (int i = 0; i < (1 << n + 1) - 2; ++i) {
			scanf("%d", a + i);
		}
		printf("%d\n", solve());
	}
	return 0;
}