def abs(p): if p<0: p*=-1 return p X,Y=(int(i) for i in input(). split ()) x=abs(X) y=abs(Y) if x<y: m=y ot=x else: m=x ot=y if m==0 or m==1 or m==3: print ("YES") elif m<=4: if ot!=m: print ("YES") else: print("NO") elif m==5: if ot==0 or ot==2 or ot==4: print ("YES") else: print ("NO") elif m==6: if ot==1 or ot==3: print ("YES") else: print ("NO") else: print ("NO")