# https://yukicoder.me/problems/no/3694

from collections import deque

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

    queue = deque()
    patterns = [-1] * N
    for s_i in range(N):
        if patterns[s_i] == -1:
            queue.append(s_i)
            patterns[s_i] = 0
            while len(queue) >0:
                v = queue.popleft()
                for w in next_nodes[v]:
                    if patterns[w] == -1:
                        patterns[w] = 1 - patterns[v]
                        queue.append(w)
                    elif patterns[w] == patterns[v]:
                        print("No")
                        return
    print("Yes")



if __name__ == "__main__":
    main()