Sum the nth value for every key in a python dictionary [closed]

Question

EDIT

I have the following dictionary:

dictionary = {'abc': [20, 'john'], 'def': [25, 'jim'], 'ghi': [30, 'jack']}

I would like to sum all of the first values for each key and define it as a variable

Expected answer:

20 + 25 + 30

total_score = 75