#!/usr/bin/python

#* encoding=utf-8

s = "20-5*(0+1)*5^(6-2^2)"

c = 0

top = [0,s[c],0]

op = [["0","1","2","3","4","5","6","7","8","9"],["+","-"],["*","/"],["^"]]

def getLev(ch):

    for c1 in range(0, len(op)):

        for c2 in range(0, len(op[c1])):

            if (op[c1][c2]==ch):

                return c1

            elif (len(ch)>1):

                match = 0

                for c3 in range(0, len(ch)):

                    if (getLev(ch[c3])>=0):

                        match+=1

                if (match==len(ch)):return c1

    return -1

def makeTree(root):

    global c

    global s

    c += 1

    if (c>=len(s)):

        return root

    if (s[c]=="("):

        c+=1

        node = [0, s[c], 0]

        node = makeTree(node)

    elif (s[c]==")"):

        return root

    else: node=[0, s[c], 0]

    levRoot = getLev(root[1])

    levCur = getLev(node[1])

    print levRoot, levCur, root[1], node[1]

    if (levCur>=levRoot):

        if ((levRoot==0 and levCur!=levRoot)

        or (levRoot!=0 and levCur==levRoot)):

            node[0] = root

            root = node

            return makeTree(root)

        elif (levRoot==0 and levCur==0):

            root[1] += node[1]

            return makeTree(root)

        else:

            node[0] = root[2]

            root[2] = makeTree(node)

            return makeTree(root)

    else:

        if (levCur==0 or node[0]!=0):

            root[2] = node

            return makeTree(root)

        else:

            c-=1

            return root

top = makeTree(top)

#print top 

def getTree(node):

    ret = [] 

    if (node[0]!=0):

        _tmp = getTree(node[0])

        for c in range(0, len(_tmp)):

            ret.append(_tmp[c])

    if (node[2]!=0):

        _tmp = getTree(node[2])

        for c in range(0, len(_tmp)):

            ret.append(_tmp[c])

    ret.append(node[1])

    return ret 

exp = getTree(top)

print exp 

def calc():

    stack=[]

    for c in range(0, len(exp)):

        if (exp[c]>='0' and exp[c]<='9'):

            stack.append(exp[c])

        else:

            op = exp[c]

            n2 = stack.pop()

            n1 = stack.pop()

            if (op!="^"):

                v = n1+op+n2

            else:

                v = "pow(%s,%s)"%(n1,n2)

            print v, eval(v)

            stack.append("%s"%eval(v))

    return stack.pop()

print calc()