I got my code to check for how many digits that i type in my raw input

```
num = int(raw_input("Enter, "))
import math
digits = int(math.log10(num))+1
print digits
```

example 1587898 then it prints 7 digits

I need my code to calculate the digits i type in my raw input until it reaches a single digit

for example i type 4569841. then it will add those numbers 4+5+6+9+8+4+1

it will print 37. it will continue to add 3 + 7 and it will print 10. It continues to add again 1+0 and prints 1 and it stops there because 1 is a single digit.

I can't seem to figure out and what code i need to add the digits together.

I think i am suppose to use a while loop like this

`while digits >1:`

and it will continue to add the number as long as digit is greater then 1 but i am not sure what code i need to sum up the numbers i type.