题解 | #完全数计算#

def perfect(num):
    list_ = [1]
    a = 0
    for i in range(2, int(num**0.5)+1):
        if num % i == 0:
            list_.append(i)
            list_.append(num//i)
    for i in list_:
        a += i
    if a == num:
        return 1
    else:
        return 0


nout = 0
for i in range(int(input())+1):
    nout += perfect(i)
print(nout-1)