import random
n=int(input())
s=1
if n>2:
	k,m=0,n-1
	while m&1==0: k+=1; m>>=1
	
	def p(n):
		a=random.randint(2,n-1)
		b=pow(a,m,n)
		if b==1: return False
		for i in range(k):
			if b==n-1: return False
			b=pow(b,2,n)
		return True
		
	for i in [0]*100:
		if p(n): s=0
print(["YES","NO"][s])