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

#define QwQ330AwA return 0
#define ll long long

const int N = 250005;
bool vis[N];
vector <int> e[N];
int w[N];
int n, m;
mt19937 rnd(time(0));

void solve() {
	cin >> n >> m;
	for (int i = 1; i <= n; i++) vis[i] = 0, e[i].clear(), w[i] = rnd() % 2;
	for (int i = 1, u, v; i <= m; i++) {
		cin >> u >> v;
		e[u].push_back(v);
		e[v].push_back(u);
	}
	queue <int> q;
	auto check = [&](int x) -> void {
		if (vis[x]) return ;
		int cnt = 0;
		for (auto v : e[x]) {
			if (w[x] == w[v]) cnt++;
		}
		if (cnt >= 2) q.push(x), vis[x] = 1;
	};
	for (int i = 1; i <= n; i++) check(i);
	int lim = n * 8 + 330;
	int tot = 0;
	while (!q.empty()) {
		int u = q.front();
		tot++;
		if (tot >= lim) break;
		q.pop();
		vis[u] = 0;
		int cnt = 0;
		for (auto v : e[u]) {
			if (w[u] == w[v]) cnt++;
		}
		if (cnt < 2) continue;
		w[u] ^= 1;
		for (auto v : e[u]) check(v);
	}
	if (tot >= lim) cout << "-1" << '\n';
	else {
		for (int i = 1; i <= n; i++) cout << w[i] << ' ';
		cout << '\n';
	}
}

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int t;
	cin >> t;
	while (t--) solve();
	QwQ330AwA;
}