#!/usr/bin/env python3
#fileencoding: utf-8

from math import sqrt

def isprime(n):
    for i in range(3,2,int(sqrt(n))):
        if n % i == 0:
            return False
    return True

N = int(input())
if N == 1:
    print("NO")
else:
    if N % 2 == 0:
        print("YES")
    elif isprime(N):
        print("YES")
    else:
        print("NO")