Didn't understand question ALPHA SCORE in Divide and conquer

#1

Hey can u explain how the example is getting answer 15 and make the question a little bit clear

#2

@this_variable
alpha score is sum of all the numbers previously seen on the stairs which are smaller than the present number
for the input
5
1 5 3 6 4

score for 1 = 0 (no number is seen until now)
score for 5 = 1 (1 is smaller than 5)
score for 3 = 1 (1 is smaller than 3)
score for 6 = 9 (1, 5, 3 smaller than 6)
score for 4 = 4 (1, 3 smaller than 4)
total score = 0 + 1 + 1 + 9 + 4 = 15