.686p
.model flat
include kernel32.inc
includelib kernel32.lib
includelib msvcrt.lib
extern _printf:proc
extern _scanf:proc
extern _strlen:proc
extern _getchar:proc
_bss segment
strbuf db 100000 dup(0)
cnt dd 256 dup(0)
_bss ends
.data
strfmt db "%s",0
strPrintfFmt db "%s",10,0
rot dd 0
.code
process_char proc
    mov eax, [esp+4]
    cmp eax, 65
    jl check_if_lower
    cmp eax, 90
    jg check_if_lower
    jmp uppercase
check_if_lower:
    cmp eax, 97
    jl end_of_proc
    cmp eax, 122
    jg end_of_proc
    
lowercase:
    sub eax, 97
    add eax, rot
    cdq
    mov ebx, 26
    idiv ebx
    add edx, 97
    mov al, dl
    jmp end_of_proc
    
uppercase:
    sub eax, 65
    add eax, rot
    cdq
    mov ebx, 26
    idiv ebx
    add edx, 65
    mov al, dl
    
end_of_proc:
    ret

process_char endp
_main proc
len=-4
    push ebp
    mov ebp, esp
    sub esp, 4

    xor ecx, ecx
    inp$start:
    push ecx
    call _getchar
    pop ecx
    cmp eax, -1
    je inp$end
    inc cnt[eax*4]
    mov byte ptr strbuf[ecx], al
    inc ecx
    jmp inp$start
    inp$end:
    mov dword ptr len[ebp], ecx
    
    xor eax, eax
    xor edx, edx
    xor ecx, ecx
    mov al, 'a'
    loop1$start:
    cmp al, 'z'
    jg loop1$end
    xor ebx, ebx
    add ebx, cnt[eax*4]
    add ebx, cnt[eax*4-128]
    cmp ebx, edx
    cmovge ecx, eax
    cmovge edx, ebx
    inc al
    jmp loop1$start
    loop1$end:
    
    sub ecx, 97
    mov eax, 4
    sub eax, ecx
    cmp eax, 0
    jge rot$set
    add eax, 26
    rot$set:
    mov rot, eax
    
    mov ecx, dword ptr len[ebp]
    test ecx, ecx
    jz for@end
for@start:
    dec ecx
    
    movzx eax, byte ptr strbuf[ecx]
    push eax
    call process_char
    add esp, 4
    
    mov byte ptr strbuf[ecx], al
    
    test ecx, ecx
    jnz for@start
for@end:
    push offset strbuf
    push offset strPrintfFmt
    call _printf
    add esp, 8
    push 0
    call ExitProcess
    leave
    ret
_main endp
end _main