N,M = map(int,input().split())
G = {i:[] for i in range(1,N+1)}
for _ in range(M):
    a,b = map(int,input().split())
    G[a].append(b)
    G[b].append(a)
Col = [-1]*(N+1)
ans = "Yes"
def dfs(v,p):
    global ans
    for u in G[v]:
        if u==p:continue
        if Col[u]==-1:
            Col[u] = 1-Col[v]
            dfs(u,v)
            if ans=="No":return
        elif Col[u]==Col[v]:
            ans = "No"
            return
Col[0] = 0
for i in range(1,N+1):
    if Col[i]==-1:
        dfs(i,0)
    if ans=="No":break
print(ans)