from collections import deque

n, m = map(int, input().split())
l = [-1] * n

to = [[] for _ in range(n)]
for _ in range(m):
    aa, bb = map(int, input().split())
    aa -= 1
    bb -= 1
    to[aa].append(bb)
    to[bb].append(aa)

for i in range(n):
    if l[i] != -1:
        continue
    l[i] = 0
    q = deque([i])
    while q:
        v = q.popleft()
        for u in to[v]:
            if l[u] != -1:
                if l[u] == l[v]:
                    print("No")
                    exit()
                continue
            l[u] = 1 - l[v]
            q.append(u)

print("Yes")