user: What would the C source look like for the assembly code provided here?

```asm
<fun>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x68,%rsp
  mov    %edi,0x28(%rsp)
  movl   $0x1,0x34(%rsp)
  cmp    $0x3,%edi
  jle    L262
  lea    -0x2(%rdi),%r11d
L62:
  mov    0x28(%rsp),%eax
  sub    %r11d,%eax
  cmp    $0x3,%eax
  jle    L339
  lea    0x1(%r11),%eax
  cmp    $0x3,%eax
  jle    L49
  test   %r11d,%r11d
  jle    L49
  lea    -0x1(%r11),%eax
  movl   $0x1,0x10(%rsp)
  mov    %eax,0x38(%rsp)
  mov    %eax,0x14(%rsp)
  movl   $0x1,0x30(%rsp)
  mov    %r11d,0x3c(%rsp)
L266:
  addl   $0x1,0x10(%rsp)
  mov    0x10(%rsp),%esi
  cmp    $0x3,%esi
  jle    L213
  mov    0x14(%rsp),%ebx
  movl   $0x1,0x24(%rsp)
  lea    0x1(%rbx),%eax
  cmp    $0x3,%eax
  jle    L217
  test   %ebx,%ebx
  jle    L217
  mov    0x3c(%rsp),%r11d
  movl   $0x1,0xc(%rsp)
  sub    %esi,%r11d
  mov    %r11d,%r10d
L267:
  addl   $0x1,0xc(%rsp)
  mov    0xc(%rsp),%edx
  cmp    $0x3,%edx
  jle    L64
  lea    0x1(%r10),%eax
  movl   $0x1,0x1c(%rsp)
  cmp    $0x3,%eax
  jle    L15
  test   %r10d,%r10d
  jle    L15
  mov    0x14(%rsp),%r9d
  mov    %r10d,0x2c(%rsp)
  mov    $0x1,%r11d
  sub    %edx,%r9d
L57:
  add    $0x1,%r11d
  cmp    $0x3,%r11d
  jle    L243
  lea    0x1(%r9),%eax
  movl   $0x1,0x18(%rsp)
  cmp    $0x3,%eax
  jle    L59
  test   %r9d,%r9d
  jle    L59
  mov    0x2c(%rsp),%ecx
  mov    %r11d,0x5c(%rsp)
  mov    $0x1,%r10d
  mov    %r9d,0x20(%rsp)
  sub    %r11d,%ecx
L163:
  add    $0x1,%r10d
  cmp    $0x3,%r10d
  jle    L142
  lea    0x1(%rcx),%eax
  mov    $0x1,%r9d
  cmp    $0x3,%eax
  jle    L103
  test   %ecx,%ecx
  jle    L103
  mov    0x20(%rsp),%r15d
  mov    $0x1,%edx
  mov    %r10d,0x58(%rsp)
  sub    %r10d,%r15d
  mov    %edx,%r10d
L41:
  add    $0x1,%r10d
  cmp    $0x3,%r10d
  jle    L91
  lea    0x1(%r15),%eax
  mov    $0x1,%r8d
  cmp    $0x3,%eax
  jle    L417
  test   %r15d,%r15d
  jle    L417
  mov    %ecx,%r14d
  mov    %r10d,0x4c(%rsp)
  mov    $0x1,%r13d
  mov    %r9d,0x50(%rsp)
  sub    %r10d,%r14d
  mov    %ecx,0x54(%rsp)
  mov    %r14d,%ecx
  mov    %r8d,%r14d
L117:
  add    $0x1,%r13d
  cmp    $0x3,%r13d
  jle    L351
  lea    0x1(%rcx),%eax
  mov    $0x1,%esi
  cmp    $0x3,%eax
  jle    L406
  test   %ecx,%ecx
  jle    L406
  mov    %r15d,0x48(%rsp)
  mov    %r15d,%ebp
  mov    $0x1,%r12d
  mov    %r13d,0x40(%rsp)
  sub    %r13d,%ebp
  mov    %ecx,%r13d
  mov    %r14d,0x44(%rsp)
  mov    %esi,%r14d
L66:
  add    $0x1,%r12d
  cmp    $0x3,%r12d
  jle    L379
  lea    0x1(%rbp),%eax
  mov    $0x1,%r15d
  cmp    $0x3,%eax
  jle    L399
  test   %ebp,%ebp
  jle    L399
  mov    $0x1,%ebx
L131:
  add    $0x1,%ebx
  cmp    $0x3,%ebx
  jle    L342
  mov    $0x2,%edi
  sub    %ebx,%edi
  add    %ebp,%edi
  call   <fun>
  add    %eax,%r15d
L294:
  cmp    %ebx,%ebp
  jge    L131
L399:
  add    %r15d,%r14d
L421:
  sub    $0x1,%ebp
  cmp    %r13d,%r12d
  jle    L66
  mov    %r13d,%ecx
  mov    %r14d,%esi
  mov    0x40(%rsp),%r13d
  mov    0x44(%rsp),%r14d
  mov    0x48(%rsp),%r15d
L406:
  add    %esi,%r14d
L171:
  sub    $0x1,%ecx
  cmp    %r13d,%r15d
  jge    L117
  mov    0x4c(%rsp),%r10d
  mov    0x50(%rsp),%r9d
  mov    %r14d,%r8d
  mov    0x54(%rsp),%ecx
L417:
  add    %r8d,%r9d
L281:
  sub    $0x1,%r15d
  cmp    %ecx,%r10d
  jle    L41
  mov    0x58(%rsp),%r10d
L103:
  add    %r9d,0x18(%rsp)
L208:
  sub    $0x1,%ecx
  cmp    %r10d,0x20(%rsp)
  jge    L163
  mov    0x5c(%rsp),%r11d
  mov    0x20(%rsp),%r9d
L59:
  mov    0x18(%rsp),%edi
  add    %edi,0x1c(%rsp)
L5:
  sub    $0x1,%r9d
  cmp    0x2c(%rsp),%r11d
  jle    L57
  mov    0x2c(%rsp),%r10d
L15:
  mov    0x1c(%rsp),%edx
  add    %edx,0x24(%rsp)
L407:
  mov    0xc(%rsp),%ebx
  sub    $0x1,%r10d
  cmp    %ebx,0x14(%rsp)
  jge    L267
L217:
  mov    0x24(%rsp),%ecx
  add    %ecx,0x30(%rsp)
L231:
  subl   $0x1,0x14(%rsp)
  mov    0x3c(%rsp),%edi
  cmp    %edi,0x10(%rsp)
  jle    L266
L346:
  mov    0x30(%rsp),%esi
  add    %esi,0x34(%rsp)
L54:
  mov    0x28(%rsp),%edi
  mov    0x38(%rsp),%r11d
  mov    %edi,%eax
  sub    %r11d,%eax
  cmp    %eax,%edi
  jge    L62
L262:
  mov    0x34(%rsp),%eax
  add    $0x68,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  cs nopw 0x0(%rax,%rax,1)
L342:
  mov    $0x1,%r15d
  jmp    L294
  nopl   0x0(%rax,%rax,1)
L379:
  mov    $0x1,%r14d
  jmp    L421
  nopl   0x0(%rax,%rax,1)
L351:
  mov    $0x1,%r14d
  jmp    L171
  nopl   0x0(%rax,%rax,1)
L91:
  mov    $0x1,%r9d
  jmp    L281
  nopl   0x0(%rax,%rax,1)
L142:
  movl   $0x1,0x18(%rsp)
  jmp    L208
  nopl   (%rax)
L243:
  movl   $0x1,0x1c(%rsp)
  jmp    L5
  nopl   (%rax)
L64:
  movl   $0x1,0x24(%rsp)
  jmp    L407
  nopl   (%rax)
L213:
  movl   $0x1,0x30(%rsp)
  jmp    L231
  nopl   (%rax)
L339:
  lea    -0x1(%r11),%eax
  movl   $0x1,0x34(%rsp)
  mov    %eax,0x38(%rsp)
  jmp    L54
  nopl   (%rax)
L49:
  lea    -0x1(%r11),%eax
  movl   $0x1,0x30(%rsp)
  mov    %eax,0x38(%rsp)
  jmp    L346
```

assistant: ```c
int fun(int n) {
  int sum = 0, i;
  if (n < 4)
    return 1;
  for (i = 1; i <= n; i++) {
    if (i < 4)
      sum = 1;
    else
      sum = sum + fun(n - i + 1);
  }
  return sum;
}
```