number = 1
first_list = []
while number != '0':
number = str(input())
first_list.append(number)
if number == '0':
first_list.remove(number)
break
second_list = []
for n in first_list:
if int(n) % 3 == 0 and n[-1] == '9':
second_list.append(n)
amount = 0
for i in second_list:
amount += int(i)
print(amount)