import sys
input = sys.stdin.readline

N,M=list(map(int,input().split()))

E=[[] for i in range(N)]

for i in range(M):
    x,y=list(map(int,input().split()))
    x-=1
    y-=1
    E[x].append(y)
    E[y].append(x)

A=[-1]*N

flag=1
for i in range(N):
    if A[i]==-1:
        A[i]=0
        Q=[i]

        while Q:
            x=Q.pop()
            for to in E[x]:
                if A[to]==-1:
                    A[to]=A[x]^1
                    Q.append(to)
                else:
                    if A[to]==A[x]:
                        flag=0

if flag:
    print("Yes")
else:
    print("No")