#!/usr/bin/env python

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

__author__ = "loki"

# Usage: Make a Diy Calculator

# example:

#    '1 - 2 * ((60-30 +(-40/5) * (9-2*5/3+7/3*99/4*2998+10*568/14))-(-4*3)/(16-3*2))'

import re

RE_RULE = '\([^()]+\)'

def arithmetical(temp):

    result = eval(temp)

    return result

def main(arithmetic):

    step = 0

    while 1:

        step += 1

        result = re.search(RE_RULE, arithmetic)

        if result:  # if exist '()'

            temp_ = result.group()

            calc_res = str(arithmetical(temp_))

            arithmetic = re.sub(RE_RULE, calc_res, arithmetic, 1)  # replace  source values, Note!!! must "1" 不然会出现使用相同的结果多次替换

            print(arithmetic, "step: %s" % step)

        else:  # if not '()'

            return arithmetical(arithmetic)

if __name__ == '__main__':
    print("result: %s" % (main(user_input)))