from collections import deque

N,M=map(int,input().split())
G=[[] for i in range(N)]
for i in range(M):
    a,b=map(int,input().split())
    G[a-1].append(b-1)
    G[b-1].append(a-1)

col=[-1]*N
for i in range(N):
    if col[i]==-1:
        q=deque([(i,0)])
        while q:
            pos,c=q.popleft()
            for nx in G[pos]:
                if col[nx]==c:
                    print('No')
                    exit()
                if col[nx]==-1:
                    col[nx]=c^1
                    q.append((nx,c^1))

print('Yes')