def dfs(hp, hs):
	if hp == goal:
		return True
	ret = False
	for dx,dy in dxy:
		nxt = (hp[0]+dx, hp[1]+dy)
		if nxt not in visit and hs > 0:
			visit.add(nxt)
			ret |= dfs(nxt,hs-1)
	return ret
dxy = ((-2,-1),(-2,1),(-1,-2),(-1,2),(1,-2),(1,2),(2,-1),(2,1))
goal = tuple(map(int,raw_input().split(" ")))
visit = set([(0,0)])
print "YES" if dfs((0,0),3) else "NO"