user: 请从给定的汇编指令推导出C源代码:

```asm
<main>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  add    $0xffffffffffffff80,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  lea    D4(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    -0x70(%rbp),%rax
  mov    %rax,%rsi
  lea    D22(%rip),%rax
  mov    %rax,%rdi
  call   <scanf@plt>
  movb   $0xff,-0x71(%rbp)
  jmp    L39
L6:
  movzbl -0x71(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x71(%rbp)
L39:
  movsbl -0x71(%rbp),%eax
  cltq
  movzbl -0x70(%rbp,%rax,1),%eax
  test   %al,%al
  jne    L6
  movzbl -0x71(%rbp),%eax
  and    $0x1,%eax
  test   %al,%al
  jne    L45
  lea    D21(%rip),%rax
  mov    %rax,%rdi
  call   <puts@plt>
  jmp    L121
L45:
  movzbl -0x71(%rbp),%eax
  mov    %eax,%edx
  shr    $0x7,%dl
  add    %edx,%eax
  sar    %al
  add    $0x1,%eax
  mov    %al,-0x71(%rbp)
  movb   $0x1,-0x74(%rbp)
  jmp    L100
L31:
  movb   $0x0,-0x72(%rbp)
  movb   $0x1,-0x73(%rbp)
  jmp    L148
L103:
  mov    $0x20,%edi
  call   <putchar@plt>
  movzbl -0x73(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x73(%rbp)
L148:
  movzbl -0x73(%rbp),%eax
  cmp    -0x74(%rbp),%al
  jl     L103
  movb   $0x1,-0x73(%rbp)
  jmp    L227
L81:
  cmpb   $0x1,-0x73(%rbp)
  je     L38
  movsbl -0x73(%rbp),%eax
  movsbl -0x71(%rbp),%edx
  movsbl -0x74(%rbp),%ecx
  sub    %ecx,%edx
  add    %edx,%edx
  add    $0x1,%edx
  cmp    %edx,%eax
  jne    L4
L38:
  movsbl -0x74(%rbp),%eax
  lea    -0x1(%rax),%edx
  movsbl -0x72(%rbp),%eax
  add    %edx,%eax
  cltq
  movzbl -0x70(%rbp,%rax,1),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <putchar@plt>
  jmp    L74
L4:
  mov    $0x20,%edi
  call   <putchar@plt>
L74:
  movzbl -0x72(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x72(%rbp)
  movzbl -0x73(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x73(%rbp)
L227:
  movsbl -0x73(%rbp),%eax
  movsbl -0x71(%rbp),%edx
  movsbl -0x74(%rbp),%ecx
  sub    %ecx,%edx
  add    %edx,%edx
  add    $0x1,%edx
  cmp    %edx,%eax
  jle    L81
  mov    $0xa,%edi
  call   <putchar@plt>
  movzbl -0x74(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x74(%rbp)
L100:
  movzbl -0x74(%rbp),%eax
  cmp    -0x71(%rbp),%al
  jle    L31
  movb   $0x2,-0x74(%rbp)
  jmp    L136
L21:
  movb   $0x0,-0x72(%rbp)
  movb   $0x1,-0x73(%rbp)
  jmp    L192
L144:
  mov    $0x20,%edi
  call   <putchar@plt>
  movzbl -0x73(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x73(%rbp)
L192:
  movsbl -0x73(%rbp),%eax
  movsbl -0x71(%rbp),%edx
  movsbl -0x74(%rbp),%ecx
  sub    %ecx,%edx
  cmp    %edx,%eax
  jle    L144
  movb   $0x1,-0x73(%rbp)
  jmp    L25
L36:
  cmpb   $0x1,-0x73(%rbp)
  je     L33
  movsbl -0x73(%rbp),%eax
  movsbl -0x74(%rbp),%edx
  add    %edx,%edx
  sub    $0x1,%edx
  cmp    %edx,%eax
  jne    L37
L33:
  movsbl -0x71(%rbp),%eax
  movsbl -0x74(%rbp),%edx
  sub    %edx,%eax
  mov    %eax,%ecx
  movsbl -0x72(%rbp),%eax
  add    %ecx,%eax
  cltq
  movzbl -0x70(%rbp,%rax,1),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <putchar@plt>
  jmp    L20
L37:
  mov    $0x20,%edi
  call   <putchar@plt>
L20:
  movzbl -0x72(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x72(%rbp)
  movzbl -0x73(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x73(%rbp)
L25:
  movsbl -0x74(%rbp),%eax
  lea    (%rax,%rax,1),%edx
  movsbl -0x73(%rbp),%eax
  cmp    %eax,%edx
  jg     L36
  mov    $0xa,%edi
  call   <putchar@plt>
  movzbl -0x74(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x74(%rbp)
L136:
  movzbl -0x74(%rbp),%eax
  cmp    -0x71(%rbp),%al
  jle    L21
  mov    $0x0,%eax
L121:
  mov    -0x8(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L71
  call   <__stack_chk_fail@plt>
L71:
  leave
  ret
```

tool_calls: name: unpack_data
arguments: data_label: D4
datatype: string
name: unpack_data
arguments: data_label: D22
datatype: string
name: unpack_data
arguments: data_label: D21
datatype: string

tool: D4: Enter the string : 

tool: D22: %s

tool: D21: 

String length is even


assistant: ```c
int main(void) {
  char str[100], i, j, k, n;
  printf("Enter the string : ");
  scanf("%s", str);
  for (n = -1; str[n]; n++)
    ;
  if (n % 2 == 0) {
    printf("\n\nString length is even\n\n");
    return;
  }
  n = n / 2 + 1;
  for (i = 1; i <= n; i++) {
    k = 0;
    for (j = 1; j < i; j++)
      printf(" ");
    for (j = 1; j <= 2 * (n - i) + 1; j++) {
      if (j == 1 || j == 2 * (n - i) + 1)
        printf("%c", str[i - 1 + k]);
      else
        printf(" ");
      k++;
    }
    printf("\n");
  }
  for (i = 2; i <= n; i++) {
    k = 0;
    for (j = 1; j <= n - i; j++)
      printf(" ");
    for (j = 1; j <= 2 * i - 1; j++) {
      if (j == 1 || j == 2 * i - 1)
        printf("%c", str[n - i + k]);
      else
        printf(" ");
      k++;
    }
    printf("\n");
  }
}
```