a: dw 1
b: dw 1
h: dw 1
result: dw 1

mov word[a], 3
mov word[b], 3
mov word[h], 3
mov ax, [a]
mov bx, [b]
add ax, bx
mov bx, 2
div bx
mov bx, [h]
mul bx
and ax, 00ffh
mov word[result], ax