Fixing UVa runtime error python

After checking the output of both the debug examples and testcases from the forum I've decided to submit my code to the judge. The problem is Tree Summing, my idea is to use the tree's own nested structure, so one just needs to format the string and use eval. After getting a List it's pretty easy to check whether there's a solution or not. My suspicion is that the RE might be caused by the eval command, or is it some tricky testcase?

import re

def updateStack(string, stack):
    for i in string:
        if i == '(':
            stack += 1
        elif i == ')':
            stack -= 1
    return stack

def inputScan(string, s):
    stack = updateStack(string, s)
    if stack == 0:
        return string
    else:
        new = input()
        return string + inputScan(new, stack)

def traverse(T, num): 
    if len(T) == 0:
        return False
    elif len(T[1]) + len(T[2]) == 0:
        return T[0] == num
    return traverse(T[1], num - int(T[0])) or traverse(T[2], num - int(T[0]))

while True:
    try:
        input_ = input()
    except EOFError:
        break
    num, treeInput = input_.split(" ", 1)
    treeInput = inputScan(treeInput, 0)
    str2List = treeInput.replace("(",",[").replace(")","]")
    pattern = re.compile(r's+')
    str2List = re.sub(pattern, '', str2List)[1:]
    Tree = eval(str2List)
    f = lambda x: "yes" if x == True else "no"
    print(f(traverse(Tree, int(num))))

Tested inputs:

22 (5(4(11(7()())(2()()))()) (8(13()())(4()(1()()))))
20 (5(4(11(7()())(2()()))()) (8(13()())(4()(1()()))))
10 (3
     (2 (4 () () )
        (8 () () ) )
     (1 (6 () () )
        (4 () () ) ) )
5 ()
0 ()
-1 (-1()())
77 (77(1()())())
-77 (-77()())
-7 (1 (-6 (2 (1 ()()) (-4 ()(1 (1 ()())(-1 ()())
   ) ) )
      () ) () )
0 ()
3 (3 (4 (5 ()()) (8 (-3 (-7 ()())())(-4 ()(-8 ()()))))
(6 (6 (-5 ()())(-6 ()(-9 ()())))(7 ()())))
0 (1()
        (-2 () (1()())))
1 (1 () (0 ()()) )
0 (0 ()())
8 (8(2(1()())())())
8 (8(3(7()())())())
4 (4(2(4()())())())
5 (5(4()(1(7(3()())(4()()))(4(3()())())))())
21 (7()(5()(5()(4(1(7()())())()))))
47 (7(9()(1(4()(7()(5(9(3(4(10()())())())(5(9(5(6(3(1(9()(2(3()(9(1(3(7()())(9()()))(9(5()(2()()))()))(7()())))(5(2()(6()(2()())))())))())(7()(2()(3()()))))(9()(10(4()(3()(4(3()(5()()))())))())))(3()()))())()))(6(10()())()))))()))())
24 (9()(6()(1(2(9(8(7()())(1(1(7()())())(8()())))())(6(5(9()())())()))())))
15 (8()(3(7(4(4()(9(6(3(3()())(9(3(3(8()())(7()()))())()))(3()()))()))())())(3(1(8(5(4(2()(4()(3(1()(10()(9()())))())))())(2()()))())())())))
18 (4(9()())(1()(4()(9(3(9()(7()(8(6()())(5()(5()())))))(8(4()(1()()))()))()))))
38 (5
  (6
    (4
      ()()
    )
    (3
      ()()
    )
  )
  (7
    (2
      (1
        ()()
      )
      (10
         ()
         (9
           (5
             ()()
           )
           (2
             ()()
           )
         )
      )
    )
    ()
  )
)

Output:

yes
no
yes
no
no
yes
no
yes
yes
no
yes
yes
yes
yes
no
no
no
no
no
no
no
no
no
yes