from collections import deque
N, M = map(int, input().split())
G = [[] for i in range(N)]
for _ in range(M):
	u, v = map(int, input().split()); u -= 1; v -= 1
	G[u].append(v)
	G[v].append(u)

A = [-1] * N
que = deque()
A[0] = 0; que.append(0)
while que:
	v = que.pop()
	for nv in G[v]:
		if A[nv] == -1:
			A[nv] = A[v] ^ 1
			que.append(nv)
		if A[nv] == A[v]:
			print("No")
			exit()
print("Yes")