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

```asm
<main>:
  endbr64
  push   %rbx
  lea    -0xf4000(%rsp),%r11
L57:
  sub    $0x1000,%rsp
  orq    $0x0,(%rsp)
  cmp    %r11,%rsp
  jne    L57
  sub    $0x250,%rsp
  lea    D18(%rip),%rdi
  mov    %fs:0x28,%rax
  mov    %rax,0xf4248(%rsp)
  xor    %eax,%eax
  mov    %rsp,%rbx
  call   <printf@plt>
  lea    D27(%rip),%rdi
  mov    %rbx,%rsi
  call   <scanf@plt>
  mov    %rbx,%rdi
  call   <strlen@plt>
  test   %eax,%eax
  jle    L214
  mov    %eax,%edx
  lea    -0x1(%rax),%eax
  cmp    $0xe,%eax
  jbe    L118
  mov    %edx,%ecx
  pxor   %xmm1,%xmm1
  pxor   %xmm6,%xmm6
  mov    %rbx,%rax
  shr    $0x4,%ecx
  pxor   %xmm4,%xmm4
  sub    $0x1,%ecx
  shl    $0x4,%rcx
  lea    0x10(%rsp,%rcx,1),%rcx
  nopl   0x0(%rax)
L3:
  movdqa (%rax),%xmm0
  movdqa %xmm6,%xmm3
  add    $0x10,%rax
  pcmpgtb %xmm0,%xmm3
  movdqa %xmm0,%xmm2
  punpcklbw %xmm3,%xmm2
  punpckhbw %xmm3,%xmm0
  movdqa %xmm4,%xmm3
  pcmpgtw %xmm2,%xmm3
  movdqa %xmm2,%xmm5
  punpcklwd %xmm3,%xmm5
  punpckhwd %xmm3,%xmm2
  movdqa %xmm0,%xmm3
  paddd  %xmm5,%xmm1
  paddd  %xmm2,%xmm1
  movdqa %xmm4,%xmm2
  pcmpgtw %xmm0,%xmm2
  punpcklwd %xmm2,%xmm3
  punpckhwd %xmm2,%xmm0
  paddd  %xmm3,%xmm1
  paddd  %xmm0,%xmm1
  cmp    %rcx,%rax
  jne    L3
  movdqa %xmm1,%xmm0
  mov    %edx,%ecx
  psrldq $0x8,%xmm0
  and    $0xfffffff0,%ecx
  paddd  %xmm0,%xmm1
  movdqa %xmm1,%xmm0
  psrldq $0x4,%xmm0
  paddd  %xmm0,%xmm1
  movd   %xmm1,%eax
  test   $0xf,%dl
  je     L172
L111:
  movslq %ecx,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0x1(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0x2(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0x3(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0x4(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0x5(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0x6(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0x7(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0x8(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0x9(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0xa(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0xb(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0xc(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  lea    0xd(%rcx),%esi
  cmp    %esi,%edx
  jle    L172
  movslq %esi,%rsi
  add    $0xe,%ecx
  movsbl (%rsp,%rsi,1),%esi
  add    %esi,%eax
  cmp    %ecx,%edx
  jle    L172
  movslq %ecx,%rcx
  movsbl (%rsp,%rcx,1),%edx
  add    %edx,%eax
  xchg   %ax,%ax
L172:
  cltd
  lea    D24(%rip),%rdi
  shr    $0x1a,%edx
  lea    (%rax,%rdx,1),%esi
  xor    %eax,%eax
  and    $0x3f,%esi
  sub    %edx,%esi
  add    $0x20,%esi
  call   <printf@plt>
  mov    0xf4248(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L90
  add    $0xf4250,%rsp
  xor    %eax,%eax
  pop    %rbx
  ret
L214:
  xor    %eax,%eax
  jmp    L172
L118:
  xor    %eax,%eax
  xor    %ecx,%ecx
  jmp    L111
L90:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: unpack_data
arguments: label: D18
datatype: string
name: unpack_data
arguments: label: D27
datatype: string
name: unpack_data
arguments: label: D24
datatype: string

tool: D18: Enter an abitrarily long string, ending with carriage return > 

tool: D27: %s

tool: D24: Check sum is %c


assistant: ```c
int main(void) {
  char string[1000000];
  char checksumchar;
  int i, stringlength, checksum_summation;
  printf("Enter an abitrarily long string, ending with carriage return > ");
  scanf("%s", string);
  stringlength = strlen(string);
  checksum_summation = 0;
  for (i = 0; i < stringlength; i++) {
    checksum_summation += (int)string[i];
  }
  checksum_summation %= 64;
  checksum_summation += 32;
  checksumchar = (char)checksum_summation;
  printf("Check sum is %c\n", checksumchar);
  return 0;
}
```