Google Treasure solution in python - first time python user, help whats wrong

[x40]

I try to learn python thru solving some interisting problem, found
google trasure hunt,
write first program ( but cant find whats wrong).

# Unzip the archive, then process the resulting files to obtain a
numeric result. You'll be taking the sum of lines from files matching
a certain description, and multiplying those sums together to obtain a
final result. Note that files have many different extensions, like
'.pdf' and '.js', but all are plain text files containing a small
number of lines of text.
#
#Sum of line 5 for all files with path or name containing abc and
ending in .js
#Sum of line 5 for all files with path or name containing HIJ and
ending in .js
#Hint: If the requested line does not exist, do not increment the sum.
#
#Multiply all the above sums together and enter the product below.
#(Note: Answer must be an exact, decimal representation of the
number.)

import fnmatch
import os

def zbrojipl(pattern):
    rootPath = ''
    sum1=0
    for root, dirs, files in os.walk(rootPath):
     for filename in files:
      path=os.path.join(root, filename)
      if fnmatch.fnmatch(path, pattern):
        #print path
        f=open(path)
        redovi=f.readlines()
        #print len(redovi),redovi
        if len(redovi)>=5:
            #print redovi[4] # index od 0 kao C
            sum1=sum1+int(redovi[4])
    return sum1

print zbrojipl('*[abc]*.js')*zbrojipl('*[HIJ]*.js')