Can anyone please write editorial for this problem or tell me the logic?

Project of code 1.0 check this

it is kind of equation but it is hard to calculate, when i used it on the example it is wrong answer, i get 8 and the answer 18 for first test case how he calculate it i don’t know the code cheff but with my eyes it is 8 ?

Total number of squares = m x (m+1) x (2m+1)/6 +
(n-m) x m x (m+1)/2

Can you please elaborate more @eng_ghanima