import sys
input = sys.stdin.readline
from collections import *

class Unionfind:
    def __init__(self, n):
        self.par = [-1]*n
        self.rank = [1]*n
    
    def root(self, x):
        r = x
        
        while not self.par[r]<0:
            r = self.par[r]
        
        t = x
        
        while t!=r:
            tmp = t
            t = self.par[t]
            self.par[tmp] = r
        
        return r
    
    def unite(self, x, y):
        rx = self.root(x)
        ry = self.root(y)
        
        if rx==ry:
            return
        
        if self.rank[rx]<=self.rank[ry]:
            self.par[ry] += self.par[rx]
            self.par[rx] = ry
            
            if self.rank[rx]==self.rank[ry]:
                self.rank[ry] += 1
        else:
            self.par[rx] += self.par[ry]
            self.par[ry] = rx
    
    def is_same(self, x, y):
        return self.root(x)==self.root(y)
    
    def count(self, x):
        return -self.par[self.root(x)]

N, M = map(int, input().split())
G = [[] for _ in range(N)]
uf = Unionfind(N)

for _ in range(M):
    u, v = map(int, input().split())
    G[u-1].append(v-1)
    G[v-1].append(u-1)
    uf.unite(u-1, v-1)

rs = set(uf.root(v) for v in range(N))
color = [0]*N

for r in rs:
    q = deque([r])
    color[r] = 1
    odd_cycle = False
    
    while q:
        v = q.popleft()
        
        for nv in G[v]:
            if color[nv]==0:
                color[nv] = -color[v]
                q.append(nv)
            else:
                if color[v]==color[nv]:
                    odd_cycle = True
    
    if not odd_cycle:
        exit(print('No'))

print('Yes')