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

```asm
<main>:
  endbr64
  push   %r14
  push   %r13
  mov    %rsi,%r13
  push   %r12
  push   %rbp
  sub    $0x8,%rsp
  cmp    $0x4,%edi
  je     L26
  mov    (%rsi),%rsi
  lea    D31(%rip),%rdi
  xor    %eax,%eax
  call   <printf@plt>
  mov    $0x1,%edi
  call   <exit@plt>
L26:
  mov    0x8(%r13),%rdi
  lea    D28(%rip),%rsi
  call   <fopen@plt>
  mov    %rax,%r12
  test   %rax,%rax
  je     L25
L4:
  mov    0x10(%r13),%rdi
  lea    D44(%rip),%rsi
  call   <fopen@plt>
  mov    %rax,%rbp
  test   %rax,%rax
  je     L44
L85:
  mov    0x18(%r13),%rdi
  xor    %edx,%edx
  xor    %esi,%esi
  call   <strtol@plt>
  mov    %eax,%r13d
  test   %eax,%eax
  js     L88
L67:
  mov    %r13d,%edx
  mov    %r13d,%esi
  lea    D41(%rip),%rdi
  xor    %eax,%eax
  call   <printf@plt>
  mov    %r13d,%edi
  call   <malloc@plt>
  mov    %rax,%r14
  test   %rax,%rax
  jne    L1
  jmp    L49
  nopl   0x0(%rax,%rax,1)
L79:
  mov    %rbp,%rcx
  mov    %r13d,%edx
  mov    $0x1,%esi
  mov    %r14,%rdi
  call   <fwrite@plt>
L1:
  mov    %r12,%rcx
  mov    %r13d,%edx
  mov    $0x1,%esi
  mov    %r14,%rdi
  call   <fread@plt>
  cmp    %eax,%r13d
  je     L79
  mov    %r13d,%edx
  mov    $0xff,%esi
  sub    %eax,%edx
  cltq
  lea    (%r14,%rax,1),%rdi
  call   <memset@plt>
  mov    %rbp,%rcx
  mov    %r13d,%edx
  mov    $0x1,%esi
  mov    %r14,%rdi
  call   <fwrite@plt>
  mov    %r14,%rdi
  call   <free@plt>
  mov    %r12,%rdi
  call   <fclose@plt>
  mov    %rbp,%rdi
  call   <fclose@plt>
  add    $0x8,%rsp
  xor    %eax,%eax
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
L49:
  lea    D49(%rip),%rdi
  call   <puts@plt>
  mov    $0x1,%edi
  call   <exit@plt>
  jmp    L1
L88:
  lea    D49(%rip),%rdi
  call   <puts@plt>
  mov    $0x1,%edi
  call   <exit@plt>
  jmp    L67
L44:
  mov    0x10(%r13),%rsi
  lea    D53(%rip),%rdi
  xor    %eax,%eax
  call   <printf@plt>
  mov    $0x1,%edi
  call   <exit@plt>
  jmp    L85
L25:
  mov    0x8(%r13),%rsi
  lea    D53(%rip),%rdi
  xor    %eax,%eax
  call   <printf@plt>
  mov    $0x1,%edi
  call   <exit@plt>
  jmp    L4
```

tool_calls: name: retrieve_data
arguments: data_label: D31
datatype: string
name: retrieve_data
arguments: data_label: D28
datatype: string
name: retrieve_data
arguments: data_label: D44
datatype: string
name: retrieve_data
arguments: data_label: D41
datatype: string
name: retrieve_data
arguments: data_label: D49
datatype: string
name: retrieve_data
arguments: data_label: D53
datatype: string

tool: D31: usage: %s InputFile PaddedFile BlockSize


tool: D28: rb

tool: D44: wb

tool: D41: blocksize = %d (0x%0x)


tool: D49: Error in blocksize

tool: D53: Error opening %s


assistant: ```c
int main(int argc, char *argv[]) {
  FILE *fin, *fout;
  char *buf;
  int n;
  int blocksize;
  if (argc != 4) {
    printf("usage: %s InputFile PaddedFile BlockSize\n", argv[0]);
    exit(1);
  }
  fin = fopen(argv[1], "rb");
  if (fin == NULL) {
    printf("Error opening %s\n", argv[1]);
    exit(1);
  }
  fout = fopen(argv[2], "wb");
  if (fout == NULL) {
    printf("Error opening %s\n", argv[2]);
    exit(1);
  }
  blocksize = strtol(argv[3], NULL, 0);
  if (blocksize < 0) {
    printf("Error in blocksize\n");
    exit(1);
  }
  printf("blocksize = %d (0x%0x)\n", blocksize, blocksize);
  buf = (char *)malloc(blocksize);
  if (buf == NULL) {
    printf("Error in blocksize\n");
    exit(1);
  }
  while ((n = fread(buf, sizeof(char), blocksize, fin)) == blocksize) {
    fwrite(buf, sizeof(char), blocksize, fout);
  }
  memset(buf + n, 0xff, blocksize - n);
  fwrite(buf, sizeof(char), blocksize, fout);
  free(buf);
  fclose(fin);
  fclose(fout);
  return 0;
}
```