from collections import defaultdict, deque

n, m = map(int, input().split())
G = defaultdict(list)
for _ in range(m):
    a, b = map(int, input().split())
    a -= 1
    b -= 1
    G[a].append(b)
    G[b].append(a)

visited = [[False, False] for _ in range(n)]
for i in range(n):
    if visited[i][0] and visited[i][1]:
        continue
    if visited[i][0] and not visited[i][1]:
        print("No")
        exit()
    if not visited[i][0] and visited[i][1]:
        print("No")
        exit()
    Que = deque([(i, 0)])
    visited[i][0] = True
    while Que:
        cp, cf = Que.popleft()
        nf = 1 ^ cf
        for np in G[cp]:
            if visited[np][nf]:
                continue
            visited[np][nf] = True
            Que.append((np, nf))
for i in range(n):
    if not visited[i][0] or not visited[i][1]:
        print("No")
        exit()
print("Yes")