题解 | #完全数计算#

'''
l=[0,1,2,3,6]
print(sum(l[:-1])==l[4])
100
1    2   4   5   10
100  50  25  20  10
'''

n=int(input())
cnt=0
for each in range(1,n+1):
    factor=[]
    for i in range(1,int(each**0.5)+1):
        if each%i == 0:
            factor.append(i)
            factor.append(int(each/i))
    factor.sort()
    #print(factor)
    if sum(factor[:-1])==factor[-1] and len(factor)>2:
        cnt += 1
        #print(factor[-1])
print(cnt)