t=int(input())

for i in range(t):
    n, m = map(int, input().split())
    graph = [[] for _ in range(n)]
    for _ in range(m):
        a, b = map(int, input().split())
        graph[a-1].append(b-1)
        graph[b-1].append(a-1)  # 有向グラフなら消す
    l=[]
    if n==1:
        print("No")
    else:
        print("Yes")