def wanMeiShu(n):
   s = 0
   for i in range(1,n):
      if n % i == 0:
         s += i
   if s == n :
       return 1
   else:
       return 2
n=int(input())
s=0
for i in range(1,n + 1):
   if wanMeiShu(i) == 1:
   	s+=1
print(s)
        
            
/**************************************************************
	Problem: 1150
	User: admin
	Language: Python
	Result: Accepted
	Time:104 ms
	Memory:34480 kb
****************************************************************/