#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define ll long long
#define rep(i, n) for (int i = 0; i < (n); i++)
#define coutf(f) cout << fixed << setprecision(f)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()

void solve() {
	int n, m;
	cin >> n >> m;
	vector<vector<int>> G(n);
	rep(i, m) {
		int u, v;
		cin >> u >> v;
		u--; v--;
		G[u].push_back(v);
		G[v].push_back(u);
	}
	vector<int> v(n);
	rep(i, n) v[i] = G[i].size();
	sort(all(v));
	rep(i, n) {
		auto iter1 = lower_bound(all(v), v[i]);
		auto iter2 = upper_bound(all(v), v[i]);
		if (iter2 - iter1 != 1) {
			cout << "Yes" << endl;
			return;
		}
	}
	cout << "No" << endl;
	return;
}

int main() {
	int t;
	cin >> t;
	while (t--) solve();
	return 0;
}