Lst = input(">>")
Lst = Lst.split(',')
def abs_sum(L):
if len(L) == 1:
return abs(int(L[0]))
else:
return abs(int(L[-1])) + abs_sum(L[:-1])
res = abs_sum(Lst)
print(res)
def abs_sum(L):
if len(L)==1:
return int(L[0])
L = list(map(int,L))
L[0] += L.pop()
return abs_sum(L)