section .data                                                                            
    inputmsg db "Enter number: "
    junk     db " ", 0
    number   db "  ", 0
    output   db "     "

section .text
    global _start

_start:

    ; prompt user to enter a number
    ; using write syscall (1 in rax)
    ;
    mov rax, 1
    mov rdi, 1
    mov rsi, inputmsg
    mov rdx, 14
    syscall

    ; obtain input from user
    ; using read syscall (stdin)
    ;
    mov rax, 0
    mov rdi, 0
    mov rsi, number
    mov rdx, 2
    syscall

    ; get rid of the newline
    ;
    mov rax, 0
    mov rdi, 0
    mov rsi, junk
    mov rdx, 1
    syscall

    ; get the one's place value (copy byte from number "array" into register)
    ;
    mov rax, 0
    mov al,  [number+1]
    sub al,  0x30
    cmp al,  0x5
    jne exit
    mov bl,  5
    mul bl
    mov r8, rax ; save our integer 25 into r8
    ; get the ten's place value
    ;
    mov rax, 0
    mov al,  [number+0]
    sub al,  0x30
    mov bl,  al
    add bl,  1
    mul bl
    mov r9,  rax ; save our integer into r9

    ; itoa (convert integers back to ascii)
    ;
    mov bl,  10
    div bl
    mov cl,  ah        ; copy remainder into c register
    and ax,  0x00FF    ; preserve just the quotient
    add al,  0x30      ; ASCII-ify our integer value
    mov [output+0], al ; place it in our memory
    add cl,  0x30      ; ASCII-ify our remainder value
    mov [output+1], cl ; place it in our memory

    mov rax, r8        ; copy 25 into A register
    mov bl,  10        ; set up for division
    div bl             ; divide
    mov cl,  ah        ; save remainder (5)
    and ax,  0x00FF    ; mask it
    add al,  0x30      ; ASCII-ify the 2
    mov [output+2], al ; store it

    add cl,  0x30      ; ASCII-ify 5
    mov [output+3], cl ; store it
    mov rax, 10        ; place a 10 (ASCII newline) in A reg
    mov [output+4], al ; pad newline onto our ASCII string

    ; display answer (in output) to STDOUT via write syscall
    mov rax, 1
    mov rdi, 1
    mov rsi, output      
    mov rdx, 5
    syscall

    ; return (0)
exit:
    mov rax, 60
    mov rdi, 0
    syscall