from collections import deque

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

def bfs(n):
    visited[n] = 0
    que = deque()
    que.append(n)
    while que:
        n = que.popleft()
        for v in G[n]:
            if visited[v] == -1:
                visited[v] = visited[n]^1
                que.append(v)
            elif visited[v] == visited[n]:
                exit(print("No"))

visited = [-1]*N
for i in range(N):
    if visited[i] == -1:
        bfs(i)

print("Yes")