from collections import deque
def bfs(s):
    dq=deque()
    dq.append([s,0])
    global dist,flag
    dist[s]=0
    while len(dq)!=0:
        p,h=dq.popleft()
        for e in edge[p]:
            if  dist[e]==10**9:
                dq.append([e,1-h])
                dist[e]=1-h
            else:
                if dist[e]!=1-h:
                    flag=False
    return dist

N,M=map(int,input().split())
edge=[[] for _ in range(N)]
for _ in range(M):
    a,b=map(int,input().split())
    edge[a-1].append(b-1)
    edge[b-1].append(a-1)
dist=[10**9 for _ in range(N)]
flag=True
for i in range(N):
    if dist[i]==10**9:
        bfs(i)
if flag:
    print('Yes')
else:
    print('No')