Restricted sum error

I would like to give some feedback about ...

From: http://www.checkio.org/mission/restricted-sum/solve/

HTTP_USER_AGENT:

Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.89 Safari/537.36

count = 0 result = 0 def checkio(data): global count global result if count < len(data): result += data[count] count += 1 checkio(data)

return result

This gives me the right answer when i use "Try It" function, but wrong when i try to finish task.