.intel_syntax noprefix
    .global _start
    .text
    #include<sys/syscall.h>

_start:
    push r12 //pointer to Heap beginning
    push r13 //pointer to end
    push r14 //cur
    push r15
    push rbx
    mov rbx, rsp


    mov rax, SYS_brk
    mov rdi, 0
    syscall
    mov r12, rax
    mov r14, r12

    mov rax, SYS_brk
    mov rdi, 66060288
    syscall

read_cycle:
    mov rax, SYS_read
    mov rdi, 0
    mov rsi, r14
    mov rdx, 66060288
    syscall

    cmp rax, 0
    jle next
    add r14, rax
    jmp read_cycle

next:
    cmp r14, r12
    je exit
    mov rax, SYS_write
    mov rdi, 1
    mov rsi, ptr
    mov rdx, 1

    mov r15, 0 //curNumberBefore/n

print_cycle:
    cmp r14, r12
    jl last
    mov rdi, 0
    mov dl, byte ptr [r14]
    cmp dl, const
    je then

after:
    add r15, 1
    sub r14, 1
    je print_cycle

then:
    mov rdx, r15
    mov rax, SYS_write
    mov rdi, 1
    mov rsi, r14
    sub r14, 1
    sub r15, 1
    syscall

    mov r15, 1
    jmp after

last:
    mov rdx, r15
    mov rax, SYS_write
    mov rdi, 1
    mov rsi, r14
    syscall

    mov r15, 0
    jmp exit

exit:

    pop rbx
    pop r15
    pop r14
    pop r13
    pop r12

    mov rax, SYS_exit
    mov rdi, 0
    syscall

const:
    .byte '\n'
ptr:
    .quad const