N,M = map(int,input().split())
AB = [list(map(int,input().split())) for _ in range(M)]
E = [[] for _ in range(N)]
for a,b in AB:
    E[a-1].append(b-1)
    E[b-1].append(a-1)
C = [-1] * N
C[0] = 0
def bfs(x):
    for y in E[x]:
        if C[y] == C[x]:
            print("No")
            exit()
        if C[y] == -1:
            C[y] = C[x] ^ 1
            bfs(y)


bfs(0)
print("Yes")