user: Converte this assembly snippet into its equivalent C code:

```asm
<main>:
  endbr64
  push   %r15
  xor    %r15d,%r15d
  push   %r14
  push   %r13
  xor    %r13d,%r13d
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  cmp    $0x1,%edi
  jg     L82
L164:
  mov    D0(%rip),%r12
  mov    D14(%rip),%r14
L170:
  xor    %ebx,%ebx
  jmp    L191
  nopl   0x0(%rax,%rax,1)
L85:
  cmp    $0x8,%ebp
  je     L1
  add    $0x1,%ebx
  cmp    $0xa,%ebp
  je     L185
L201:
  test   %r13d,%r13d
  je     L134
  cmp    %r13d,%ebx
  jge    L111
L134:
  mov    (%r14),%esi
  mov    %ebp,%edi
  call   <putc@plt>
L191:
  mov    (%r12),%edi
  call   <getc@plt>
  mov    (%r12),%edi
  movsbl %al,%ebp
  call   <feof@plt>
  test   %rax,%rax
  jne    L133
  cmp    $0x9,%ebp
  jne    L85
  add    $0x8,%ebx
  and    $0xfffffff8,%ebx
  jmp    L201
  nopl   0x0(%rax,%rax,1)
L1:
  cmp    $0x1,%ebx
  adc    $0xffffffff,%ebx
  jmp    L201
  nopl   0x0(%rax,%rax,1)
L20:
  mov    (%r14),%esi
  mov    %ebp,%edi
  call   <putc@plt>
  cmp    $0xa,%bpl
  je     L170
L60:
  mov    (%r12),%edi
  call   <getc@plt>
  mov    (%r12),%edi
  movsbl %al,%ebp
  call   <feof@plt>
  test   %rax,%rax
  je     L20
L133:
  mov    (%r14),%edi
  call   <fflush@plt>
  xor    %edi,%edi
  call   <exit@plt>
  add    $0x18,%rsp
  xor    %eax,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  xchg   %ax,%ax
L185:
  mov    (%r14),%esi
  mov    $0xa,%edi
  call   <putc@plt>
  jmp    L170
L111:
  test   %r15d,%r15d
  sete   0xf(%rsp)
  movzbl 0xf(%rsp),%eax
  cmp    %ebx,%r15d
  jg     L165
  test   %al,%al
  je     L60
  nopl   0x0(%rax,%rax,1)
L165:
  mov    (%r12),%edi
  call   <getc@plt>
  mov    (%r12),%edi
  movsbl %al,%ebp
  call   <feof@plt>
  test   %rax,%rax
  jne    L133
  cmp    $0xa,%ebp
  je     L185
  cmp    $0x9,%ebp
  je     L174
  cmp    $0x1,%ebx
  mov    %ebx,%eax
  adc    $0xffffffff,%eax
  add    $0x1,%ebx
  cmp    $0x8,%ebp
  cmove  %eax,%ebx
L137:
  cmp    %r15d,%ebx
  jl     L165
  cmpb   $0x0,0xf(%rsp)
  jne    L165
  jmp    L60
  cs nopw 0x0(%rax,%rax,1)
L174:
  add    $0x8,%ebx
  and    $0xfffffff8,%ebx
  jmp    L137
L82:
  mov    %edi,%ebx
  mov    0x8(%rsi),%rdi
  mov    %rsi,%rbp
  call   <getn@plt>
  mov    %eax,%r13d
  cmp    $0x2,%ebx
  je     L164
  mov    0x10(%rbp),%rdi
  call   <getn@plt>
  mov    %eax,%r15d
  jmp    L164
```

assistant: ```c
int main(int argc, char **argv) {
  register c, ct, first, last;
  first = 0;
  last = 0;
  if (argc > 1)
    first = getn(*++argv);
  if (argc > 2)
    last = getn(*++argv);
start:
  ct = 0;
loop1:
  c = getc(stdin);
  if (feof(stdin))
    goto fin;
  if (c == '\t')
    ct = (ct + 8) & ~7;
  else if (c == '\b')
    ct = ct ? ct - 1 : 0;
  else
    ct++;
  if (c == '\n') {
    putc(c, stdout);
    goto start;
  }
  if (!first || ct < first) {
    putc(c, stdout);
    goto loop1;
  }
  while (!last || ct < last) {
    c = getc(stdin);
    if (feof(stdin))
      goto fin;
    if (c == '\n') {
      putc(c, stdout);
      goto start;
    }
    if (c == '\t')
      ct = (ct + 8) & ~7;
    else if (c == '\b')
      ct = ct ? ct - 1 : 0;
    else
      ct++;
  }
  for (;;) {
    c = getc(stdin);
    if (feof(stdin))
      break;
    putc(c, stdout);
    if (c == '\n')
      goto start;
  }
fin:
  fflush(stdout);
  exit(0);
}
```