#include <iostream>

using namespace std;

struct Box {
    int Ai;
    int Bi;
};

bool compare(Box a, Box b) {
    return a.Bi > b.Bi;
}

bool judge(int V, int N, int maxAi, int maxBi, Box *boxes) {
    if (maxAi > maxBi) {
        return false;
    }
    sort(boxes, boxes + N, compare);
    for (int i = 0; i < N; i++) {
        
    }
    return true;
}

int main() {
    int T, V, N;
    Box *boxes;
    while (cin >> T) {
        for (int i = 0; i < T; i++) {
            cin >> V >> N;

            int maxAi = 0, maxBi = 0;
            int allAi = 0;
            boxes = new Box[N];
            for (int j = 0; j < N; j++) {
                Box box;
                cin >> box.Ai >> box.Bi;
                if (box.Ai > maxAi) {
                    maxAi = box.Ai;
                }
                if (box.Bi > maxBi) {
                    maxBi = box.Bi;
                }
                allAi += box.Ai;
                boxes[j] = box;
            }
            cout << (judge(V, N, maxAi, maxBi, boxes) ? "YES" : "NO") << endl;
            free(boxes);
        }
    }
    return 0;
}