# -*- coding: utf-8 -*-

from functools import reduce

def str2float(s):

    DIGITS = {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9 } 

    def str2nums(a):

        return DIGITS[a]

    def add(x, y):

        return x*10+y

    n = s.find('.')

    le = len(s[n+1:])

    p1 = map(str2nums, s[:n])

    p2 = map(str2nums, s[n+1:])

    return reduce(add, p1) + reduce(add, p2)/(10**le)