%include "io.inc"

section .data
    a dd 26
    arr db 'abcdefghijklmnopqrstuvwxyz',0

section .bss
    s resb 1

section .text
global CMAIN
CMAIN:
    mov ebp, esp; for correct debugging
    GET_DEC 4, edi
    GET_CHAR ecx
    GET_STRING s, 100
    xor ecx, ecx
    PRINT_STRING s

    .loop:
        mov esi, s
        add esi, ecx
        cmp byte[esi], 0
        jz .end
        cmp byte[esi], 'a'
        jl .continue
        cmp byte[esi], 'z'
        jg .continue
        movzx eax, byte[esi]
        sub eax, 'a'
        add eax, edi
        xor edx, edx
        div dword[a]
        mov eax, edx
        mov edx, arr
        add edx, eax
        mov dl, [edx]
        mov byte[esi], dl
        .continue:
        inc ecx
        jmp .loop

    .end:
    NEWLINE
    PRINT_STRING s
    xor eax, eax
    ret