class unif:
  def __init__(self,n):
    self.pare=[-1]*n
    self.size=[1]*n
  def root(self,x):
    while self.pare[x]!=-1:
      x=self.pare[x]
    return x
  def unite(self,u,v):
    rootu=self.root(u)
    rootv=self.root(v)
    if rootu!=rootv:
      if self.size[rootu]>=self.size[rootv]:
        self.pare[rootv]=rootu
        self.size[rootu]+=self.size[rootv]
      else:
        self.pare[rootu]=rootv
        self.size[rootv]+=self.size[rootu]
  def same(self,s,t):
    return self.root(s)==self.root(t)
N,M=map(int,input().split())
G=[[] for i in range(N)]
for i in range(M):
  a,b=map(int,input().split())
  a-=1
  b-=1
  G[a].append(b)
  G[b].append(a)
dist=[-1]*N
from collections import deque
for i in range(N):
  if dist[i]>=0:
    continue
  S=deque()
  S.append(i)
  dist[i]=0
  while S:
    x=S.pop()
    for y in G[x]:
      if dist[y]==-1:
        dist[y]=dist[x]+1
        dist[y]%=2
        S.append(y)
      else:
        if dist[y]==dist[x]:
          print('No')
          exit()
print('Yes')