how can I find the sum of total values vales after removing an element from a given pyramid [closed]

given a pyramid of bricks with a number printed on them. if we remove a brick from it then find the total sum of values of brick that will fall apart. This is the given pyramid pattern : 1 then 2 , 3 then 4 , 5 , 6 then 7 , 8 , 9 , 10 For Example : If we remove 9 then the answer will be 26.