Hello everyone.

I was attempting the credit problem in problem set 1 from CS50,

and i was stuck at adding the digits of numbers after multiplying them by 2.

When i used sum(), i got sum of numbers so if there is a two digit number in my list it will add the number itself to other single digit numbers and not the individual digits of the numbers.

For example:

```
list1 = [0,4,1,2,3,2,8,9,6]
x= int(len(list1))
## multiplying each number in list by 2.
for index in range(x):
product1 = [i*2 for i in list1]
print(product1)
this returns
>>> [0,8,2,4,6,4,16,18,12]
now if i use sum(product1)
i get 0+8+2+4+6+4+16+18+12 = 70
however, what i want to do instead is
0+8+2+4+6+4+1+6+1+8+1+2 = 43
```

how can i acheive this.

Please help.

Thanks in advance.