#! /usr/bin/python

def func8(argument):
    x = float(argument)
    acc = 0.001
    chislitel = x
    znamenatel = 1
    mnozhitel = 1
    curr_iter = 1
    prev_iter = 0

    while 1:
        chislitel = chislitel*x*x
        znamenatel = znamenatel * (mnozhitel + 1) * (mnozhitel + 2)

        slagaemoe = chislitel/znamenatel
        curr_iter = prev_iter + slagaemoe

        if slagaemoe < acc:
            return curr_iter
        mnozhitel = mnozhitel + 2
        prev_iter = curr_iter

vvod = raw_input("vvedite x: ")
print "otvet:" + str(func8(vvod))
vvod = raw_input("press any key")