user: Please show me the C implementation that matches the assembly code listed below:

```asm
<main>:
  endbr64
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  lea    -0x4000(%rsp),%r11
L33:
  sub    $0x1000,%rsp
  orq    $0x0,(%rsp)
  cmp    %r11,%rsp
  jne    L33
  sub    $0xe30,%rsp
  lea    D14(%rip),%rbp
  lea    D16(%rip),%r12
  mov    %fs:0x28,%rax
  mov    %rax,0x4e28(%rsp)
  xor    %eax,%eax
  mov    %rsp,%rbx
  jmp    L82
  nopw   0x0(%rax,%rax,1)
L131:
  mov    %rbx,%rdi
  call   <puts@plt>
L82:
  mov    %rbx,%rsi
  mov    %rbp,%rdi
  call   <scanf@plt>
  cmp    $0x1,%eax
  jne    L39
  mov    %rbx,%rdi
  call   <strlen@plt>
  mov    %rbx,%rdi
  mov    %eax,%r13d
  call   <ispalindrome@plt>
  test   %rax,%rax
  jne    L131
  test   %r13d,%r13d
  jle    L124
  movslq %r13d,%rax
  xor    %r14d,%r14d
  movzbl -0x1(%rsp,%rax,1),%edx
  add    %rbx,%rax
  jmp    L147
  nopl   (%rax)
L54:
  add    $0x1,%r14d
  sub    $0x1,%rax
  cmp    %r14d,%r13d
  je     L67
L147:
  mov    %edx,%ecx
  movzbl -0x2(%rax),%edx
  cmp    %cl,%dl
  je     L54
L67:
  mov    %r14d,%esi
  mov    %r12,%rdi
  xor    %eax,%eax
  call   <printf@plt>
  mov    %r13d,%esi
  mov    %rbx,%rdi
  sub    %r14d,%esi
  call   <lengthtobeadd@plt>
  mov    %r12,%rdi
  mov    %eax,%r14d
  mov    %eax,%esi
  xor    %eax,%eax
  call   <printf@plt>
  test   $0x1,%r14b
  jne    L86
  add    %r14d,%r14d
  sub    %r14d,%r13d
L40:
  xor    %eax,%eax
  lea    0x2710(%rsp),%r8
  test   %r13d,%r13d
  js     L80
  movslq %r13d,%rcx
  lea    0x2710(%rsp),%r8
  lea    (%rbx,%rcx,1),%rdx
  mov    %r8,%rax
  lea    0x2711(%rsp,%rcx,1),%rsi
  xchg   %ax,%ax
L127:
  movzbl (%rdx),%ecx
  add    $0x1,%rax
  sub    $0x1,%rdx
  mov    %cl,-0x1(%rax)
  cmp    %rsi,%rax
  jne    L127
  lea    0x1(%r13),%eax
  mov    $0xffffffff,%r13d
L80:
  movslq %r13d,%r13
  cltq
  mov    %r8,%rsi
  mov    %rbx,%rdi
  movb   $0x0,0x2710(%rsp,%rax,1)
  movb   $0x0,(%rsp,%r13,1)
  call   <strcat@plt>
  jmp    L131
  nop
L86:
  mov    %r14d,%eax
  sub    %r14d,%r13d
  shr    $0x1f,%eax
  add    %r14d,%eax
  sar    %eax
  sub    %eax,%r13d
  sub    $0x1,%r13d
  jmp    L40
  nopw   0x0(%rax,%rax,1)
L39:
  mov    0x4e28(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L101
  add    $0x4e30,%rsp
  xor    %eax,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
L124:
  xor    %r14d,%r14d
  jmp    L67
L101:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: extract_symbolic_data
arguments: tag: D14
type_guessed: string
name: extract_symbolic_data
arguments: tag: D16
type_guessed: string

tool: D14: %s

tool: D16: %d


assistant: ```c
int main() {
  int i, j, k, l, m, len;
  char a[10000], b[10000];
  while (scanf("%s", a) == 1) {
    l = 0;
    len = strlen(a);
    if (ispalindrome(a))
      printf("%s\n", a);
    else {
      for (i = len - 1; i >= 0; i--) {
        if (a[i] == a[i - 1]) {
          l++;
        } else
          break;
      }
      printf("%d\n", l);
      m = len - l;
      j = lengthtobeadd(a, m);
      printf("%d\n", j);
      k = 0;
      if (j % 2 == 0) {
        len = len - 2 * j;
      } else {
        len = len - j - (j / 2) - 1;
      }
      for (i = len; i >= 0; i--) {
        b[k] = a[i];
        k++;
      }
      b[k] = '\0';
      a[i] = '\0';
      strcat(a, b);
      printf("%s\n", a);
    }
  }
  return 0;
}
```