p=int(input())
O=abs(False) # 0
I=abs(True) # 1
II=abs(~True) # 2
III=sum([I,II]) # 3
a=II if p!=II else III # a=2 if p!=2 else 3 
if pow(a,~-p,p)==I and p!=sum((ord('»'),ord('»'),ord('»'))):
  print("YES")
else:
  print("NO")