n,m = map(int, input().split())
import sys
input = sys.stdin.readline
mp = map(lambda x: int(x)-1, sys.stdin.read().split())
ab = list(zip(mp,mp))

graph = [[] for i in range(n)]

for a,b in ab:
    graph[a].append(b)
    graph[b].append(a)

visited = [-1 for i in range(n)]

for i in range(n):
    if visited[i] != -1:
        continue
    visited[i] = 0
    que = [i]
    while que:
        nq = []
        while que:
            v = que.pop()
            for nv in graph[v]:
                if visited[nv] != -1:
                    if visited[nv] == visited[v]:
                        print("No")
                        exit()
                    else:
                        continue
                visited[nv] = visited[v] ^ 1
                nq.append(nv)
        que = nq

# print(visited)

print("Yes")