Prolog language

Write a predicate which processes a list of numbers by adding up every second number. The predicate is to work as shown below. (Note that you are not asked to check the input to be a valid list of numbers but can simply assume that your predicate always receive list of numbers).

?- addSecond([1,3,5,4],S). S = 7. ?- addSecond([1,3,5],S). S = 3. ?- addSecond([1,3],S). S = 3. ?- addSecond([1],S). S = 0. ?- addSecond([1,3,5],3). true.