题解 | #完全数计算#

n = int(input())
c = 0
for k in range(1,n+1):      # 所有的n
    sum = 0
    for i in range(1,int(k/2)+1):   # 所有的因子只取一半    
        if k % i == 0:
            sum += i
    if sum == k:
        c += 1
print(c)