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

// subtask 4

int main() {
    int T;
    cin >> T;
    int sumN = 0;
    while (T--) {
        int N, M;
        cin >> N >> M;
        vector<int> A(M), B(M);
        for (int i = 0; i < M; i++) {
            cin >> A[i] >> B[i];
            A[i]--;
        }
        sumN += N;
        assert(sumN <= 200'000);
        vector<int> C(M + 1);
        for (int i = 0; i < M; i++) {
            C[i + 1] = C[i] + B[i];
        }
        vector<int> E(2 * N);
        for (int i = 0; i < M; i++) {
            E[A[i] - C[i + 1] + N]++;
            E[A[i] - C[i] + N]--;
        }
        bool ok = false;
        int sum = 0;
        for (int i = 0; i < 2 * N; i++) {
            sum += E[i];
            if (sum == M) ok = true;
        }
        if (ok) cout << "Yes" << endl;
        else cout << "No" << endl;
    }
    return 0;
}