as an example, your heap would start at word 0. if your first call is myalloc(5), then you would start the header at word 1, your payload at word 2, and your footer at word 4 to meet alignment requirements. this is because the payload would have to start at an address divisible by 8, and take up two words, 5 bytes for the payload and 3 bytes of padding. so, your header would start at word 1 (address 4), the payload would start at word 2 (address 8), and your footer would start at word 4 (address 16). this would allow your next header to start at word 5 (address 20) and the next payload to start at word 6 (address 24).