#python

prod = 1

for i in range(8):

   x = int(input())

   if x > 0:

       prod *= x

print(prod)

int[] ms = {23,-235,2,6,4,5,-4,0};

ms = Arrays.stream(ms).map(num -> {

if(num>0) {

num *= 2;

}

return num;

}).toArray();