status = []
i = 0
while (i < 1000):
    status.append(False)
    i = i + 1

def go_through(student):
    student = student + 1
    length = len(status)/student
    i = 1
    while (i <= length):
        index = i *student -1
        status[index] = not (status[index])
        i = i + 1

num = int(raw_input("Enter x => "))
map(go_through, xrange(num))
print len([n for n in status if n])