An ISP is given a block of addresses starting with 190.100.0.0/16 (65,536 addresses). These addresses must further be divided into groups: (a) The first group has 64 customers; each customer requires 256 addresses. (b) The second group has 128 customers; each customer requires 128 addresses. (c) The third group has 128 customers; each customer requires 64 addresses. Design the subblocks and define the subnet range for each. How much addresses are still remaining after these allocations?