import sys,os,re;from typing import *

# calculator program
def scicalc(s):
  s=s.replace(' ','')
  if s=='':return 0
  r=doPlusMinus(s,0,len(s))
  return r

def doPlusMinus(s,a,b):
    t=s[a:b]; level=0; i=len(t)-1
    while i>=0:
        c=t[i]
        if c==')':level=level+1
        if c=='(':level=level-1
        if level==0 and (c=='+' or c=='-'):
            L=doPlusMinus(s,a,a+i);R=doMulDiv(s,a+i+1,b)
            if c=='+': return L+R
            else: return L-R
        i=i-1
    return doMulDiv(s,a,b)

def doMulDiv(s,a,b):
    t=s[a:b];level=0;i=len(t)-1
    while i >= 0:
        c=t[i]
        if c==')':level+=1
        if c=='(':level-=1
        if level==0 and(c=='*' or c=='/'):
            L = doMulDiv(s,a,a+i); R = getNum(s,a+i+1,b)
            if c=='*':return L*R
            else:
                if R==0:print("ERROR division by zero!!!") ;return 0
                return L/R
        i -= 1
    return getNum(s,a,b)

def getNum(s, a,b):
    t = s[a:b]
    if t[0]=='(' and t[-1]==')':
        return doPlusMinus(s,a+1,b-1)
    try:
        x = float(t)
    except:
        print("bad number: "+t);x=0
    return x

def main():
    Data = [
        "3 + 5",
        "10 - 2 * 3",
        "( 4 + 6 ) * 2",
        "100 / ( 5 * 2 )",
        "3.5 + 2.5 * 4",
        "( 1 + 2 ) * ( 3 + 4 )",
        "",
        "10 / 0",
        "abc + 1",
    ]
    for d in Data:
        Res=scicalc(d)
        print(d+" = "+str(Res))

main()