def sum_of_evens(lst):

   second_negative_index = next(i for i, x in enumerate(lst) if x < 0)[1]

   sum = 0

   for i in range(second_negative_index + 1, len(lst)):

       if lst[i] % 2 == 0:

           sum += lst[i]

   return sum

input_str = input()

numbers = [int(num) for num in input_str.split()]

print(sum_of_evens(numbers))