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) ans = 'Yes' C = [-1 for i in range(N)] for s in range(N): if C[s] != -1: continue C[s] = 0 todo = [s] while len(todo): s = todo.pop() for t in G[s]: if C[t] == -1: C[t] = C[s] ^ 1 todo.append(t) else: if C[s] == C[t]: print('No') exit() print(ans)