Urgent help needed in python ! Thanx

# Write a function that takes a list of integers as an argument. # The function should return a single integer that represents the # sum of any numbers in the arg list that are followed by # the same number. Here are some examples: #[4, 3, 4, 4, 3, 5, 5] #-> 9 #[4,4,4,5] #-> 8 #[5, 4, 3] #-> 0