When I run this code in Python

# Get our list from the command line

import sys

numbers = sys.argv[1].split(",")

# Your code goes here

def sum(numbers):

total = 0

for x in numbers:

total+=x

return total

print(sum(numbers))

I get an error that says:

Program Output Traceback (most recent call last): File "sum.py", line 13, in print(sum(numbers)) File "sum.py", line 10, in sum total+=x TypeError: unsupported operand type(s) for +=: 'int' and 'str' 

I don't know what the error is saying. How can I fix this?