user: Demonstrate the C code that generates the assembly output below:

```asm
<ack>:
  endbr64
  test   %edi,%edi
  je     L62
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
L203:
  lea    -0x1(%rdi),%eax
  mov    %eax,0xc(%rsp)
  test   %esi,%esi
  jne    L186
  mov    0xc(%rsp),%edx
  test   %edx,%edx
  je     L403
L105:
  mov    0xc(%rsp),%eax
L215:
  lea    -0x1(%rax),%ecx
  mov    %ecx,0x8(%rsp)
  test   %esi,%esi
  jne    L118
  mov    0x8(%rsp),%eax
  test   %eax,%eax
  je     L85
L383:
  mov    0x8(%rsp),%eax
L257:
  lea    -0x1(%rax),%r14d
  test   %esi,%esi
  jne    L295
  test   %r14d,%r14d
  je     L161
L156:
  mov    %r14d,%eax
L116:
  lea    -0x1(%rax),%r13d
  test   %esi,%esi
  jne    L225
  test   %r13d,%r13d
  je     L333
L349:
  mov    %r13d,%eax
L416:
  lea    -0x1(%rax),%edx
  test   %esi,%esi
  jne    L93
  test   %edx,%edx
  je     L270
L420:
  mov    %edx,%eax
L358:
  lea    -0x1(%rax),%r15d
  test   %esi,%esi
  jne    L82
  test   %r15d,%r15d
  je     L352
L43:
  mov    %r15d,%eax
L255:
  lea    -0x1(%rax),%r12d
  test   %esi,%esi
  jne    L114
  test   %r12d,%r12d
  je     L419
L297:
  mov    %r12d,%eax
L275:
  lea    -0x1(%rax),%ebp
  test   %esi,%esi
  jne    L155
  test   %ebp,%ebp
  je     L167
L16:
  mov    %ebp,%eax
L246:
  lea    -0x1(%rax),%ebx
  test   %esi,%esi
  jne    L219
  test   %ebx,%ebx
  je     L125
L210:
  mov    %ebx,%edi
  mov    %edx,0x4(%rsp)
  call   <ack>
  mov    0x4(%rsp),%edx
  mov    %eax,%esi
  mov    %ebx,%eax
  sub    $0x1,%eax
  jne    L246
  add    $0x1,%esi
L188:
  mov    %ebp,%eax
  sub    $0x1,%eax
  jne    L275
  add    $0x1,%esi
L205:
  mov    %r12d,%eax
  sub    $0x1,%eax
  jne    L255
  add    $0x1,%esi
L144:
  mov    %r15d,%eax
  sub    $0x1,%eax
  jne    L358
  add    $0x1,%esi
L117:
  mov    %edx,%eax
  sub    $0x1,%eax
  jne    L416
  add    $0x1,%esi
L435:
  mov    %r13d,%eax
  sub    $0x1,%eax
  jne    L116
  add    $0x1,%esi
L11:
  mov    %r14d,%eax
  sub    $0x1,%eax
  jne    L257
  add    $0x1,%esi
L170:
  mov    0x8(%rsp),%eax
  sub    $0x1,%eax
  jne    L215
  add    $0x1,%esi
L418:
  mov    0xc(%rsp),%edi
  sub    $0x1,%edi
  jne    L203
  add    $0x18,%rsp
  lea    0x1(%rsi),%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nop
L167:
  mov    $0x2,%esi
  jmp    L205
  nopw   0x0(%rax,%rax,1)
L270:
  mov    $0x2,%esi
  jmp    L435
  nopw   0x0(%rax,%rax,1)
L125:
  mov    $0x2,%esi
  jmp    L188
  nopw   0x0(%rax,%rax,1)
L419:
  mov    $0x2,%esi
  jmp    L144
  nopw   0x0(%rax,%rax,1)
L352:
  mov    $0x2,%esi
  jmp    L117
  nopw   0x0(%rax,%rax,1)
L333:
  mov    $0x2,%esi
  jmp    L11
  nopw   0x0(%rax,%rax,1)
L161:
  mov    $0x2,%esi
  jmp    L170
  nopw   0x0(%rax,%rax,1)
L219:
  sub    $0x1,%esi
  mov    %eax,%ebx
  jmp    L210
  nopw   0x0(%rax,%rax,1)
L85:
  mov    $0x2,%esi
  jmp    L418
  nopw   0x0(%rax,%rax,1)
L155:
  sub    $0x1,%esi
  mov    %eax,%ebp
  jmp    L16
  nopw   0x0(%rax,%rax,1)
L403:
  add    $0x18,%rsp
  mov    $0x2,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax)
L114:
  sub    $0x1,%esi
  mov    %eax,%r12d
  jmp    L297
  nopl   0x0(%rax,%rax,1)
L82:
  sub    $0x1,%esi
  mov    %eax,%r15d
  jmp    L43
  nopl   0x0(%rax,%rax,1)
L93:
  sub    $0x1,%esi
  mov    %eax,%edx
  jmp    L420
  nopw   0x0(%rax,%rax,1)
L225:
  sub    $0x1,%esi
  mov    %eax,%r13d
  jmp    L349
  nopl   0x0(%rax,%rax,1)
L295:
  sub    $0x1,%esi
  mov    %eax,%r14d
  jmp    L156
  nopl   0x0(%rax,%rax,1)
L62:
  lea    0x1(%rsi),%eax
  ret
  nopl   0x0(%rax)
L118:
  mov    %eax,0x8(%rsp)
  sub    $0x1,%esi
  jmp    L383
  nopl   0x0(%rax)
L186:
  mov    %edi,0xc(%rsp)
  sub    $0x1,%esi
  jmp    L105
```

assistant: ```c
int ack(int m, int n) {
  if (m == 0)
    return n + 1;
  else if (n == 0)
    return ack(m - 1, 1);
  else
    return ack(m - 1, ack(m, n - 1));
}
```