#include <algorithm>
#include <array>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iomanip>
#include <iostream>
#include <numeric>
#include <optional>
#include <queue>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

int main() {
    int32_t t;
    cin >> t;
    vector<bool> ans(t);
    for (auto i = 0; i < t; ++i) {
        int32_t n, m;
        cin >> n >> m;
        vector<int32_t> degs(n);
        for (auto j = 0; j < m; ++j) {
            int32_t u, v;
            cin >> u >> v;
            --u;
            --v;
            ++degs[u];
            ++degs[v];
        }
        unordered_map<int32_t, int32_t> hist;
        for (auto deg : degs) {
            ++hist[deg];
        }
        for (auto [k, v] : hist) {
            if (v >= 2) {
                ans[i] = true;
            }
        }
    }
    for (auto a : ans) {
        cout << (a ? "Yes" : "No") << endl;
    }
    return 0;
}