allocate-registers one, jump
allocate-registers n, result

        ; Initialize a register with the constant 1
        li one, 1

        ; Read n from input, and initialize result to 1
        read n
        li result, 1

compute:
        ; If n is zero, then we are done
        li jump, done
        jeqz n, jump

        ; Otherwise, update result and n, then loop
        mul result, result, n
        sub n, n, one
        li jump, compute
        j jump

done:
        ; Report result and halt
        write result
        halt