instr = sorted(filter(lambda x: x != 0, [int(i) for i in input().split(',')]))
pos = 1
neg = 1
lessneg = 0
for i in instr:
    if i > 0:
        pos *= i
    else:
        neg *= i
        lessneg = i
if neg > 0:
    print(pos * neg)
else:
    print(pos * (neg // lessneg))
print('f')