#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;

int N, A[202020];
ll sum = 0;

void solve() {
  int N, M;
  cin >> N >> M;
  vector<vector<int>> G(N);
  for (int i = 0; i < M; i++) {
    int u, v; cin >> u >> v;
    u--, v--;
    G[u].push_back(v);
    G[v].push_back(u);
  }
  map<int, int> mp;
  for (int i = 0; i < N; i++) {
    mp[G[i].size()]++;
  }
  for (auto p: mp) {
    if (p.second >= 2) {
      cout << "Yes" << endl;
      return;
    }
  }
  cout << "No" << endl;
}

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