bisection_method

import math

# exp(x) - 2x - 2 = 0
# x3 + 3x - 5

try:
    a = int(input())
    b = int(input())
except ValueError:
    raise ValueError('a and b must be integers')


class SameSigns(Exception):
    pass


def math_function(x):
    return math.pow(x, 3) - 3 * x - 5

def math_function2(x):
    return math.exp(x) - 2 * x - 2


def bisection_method(num1, num2, func):
    if func(num1) * func(num2) >= 0:
        raise SameSigns('f(a) and f(b) must be with different signs')
    middle = 0
    while num2 - num1 >= 0.001:
        middle = (num1 + num2) / 2
        if func(middle) * func(num1) < 0:
            num2 = middle
        else:
            num1 = middle
        if func(middle) == 0.0:
            break

    return f"{middle:.4f}"