from functools import reduce

def f1(x, y):

    return x * 10 + y

def str2float(s):

    n = 0

    while n < len(s):

        if s[n]== '.':

            break

        else:

            n = n + 1

        L1 = reduce(f1, list(map(int, s[:n])))

    return L1 + int(s[n+1:])*0.1**(len(s)-n-1)