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

```asm
<main>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x618,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x608(%rsp)
  xor    %eax,%eax
  lea    0x10(%rsp),%rbp
  lea    0x110(%rsp),%r14
  mov    %rbp,%rdi
  call   <gets@plt>
  test   %rax,%rax
  je     L97
  cs nopw 0x0(%rax,%rax,1)
L168:
  mov    %r14,%rdi
  call   <gets@plt>
  mov    %rbp,%rdi
  call   <strlen@plt>
  mov    %r14,%rdi
  movswq %ax,%r12
  call   <strlen@plt>
  movswl %r12w,%edx
  xor    %ecx,%ecx
  movswl %ax,%esi
  add    %edx,%esi
  xor    %edx,%edx
  test   %esi,%esi
  jle    L5
  nopl   (%rax)
L256:
  add    $0x1,%ecx
  movb   $0x0,0x210(%rsp,%rdx,1)
  movb   $0x0,0x410(%rsp,%rdx,1)
  movswq %cx,%rdx
  cmp    %esi,%edx
  jl     L256
L5:
  lea    -0x1(%rax),%r13d
  lea    -0x2(%r12),%eax
  mov    $0x1,%r15d
  mov    %ax,0xe(%rsp)
  lea    -0x1(%r12),%r11d
  movswq %r13w,%r10
  test   %r13w,%r13w
  js     L86
  nopw   0x0(%rax,%rax,1)
L100:
  mov    %r13d,%ebx
  sub    %r10d,%ebx
  test   %r11w,%r11w
  js     L155
  movsbl (%r14,%r10,1),%r8d
  movswq %r11w,%rsi
  xor    %ecx,%ecx
  xor    %edx,%edx
  lea    0x210(%rsp),%r9
  sub    $0x30,%r8d
  jmp    L170
  nopl   0x0(%rax,%rax,1)
L99:
  movswl %ax,%edx
  mov    %eax,%edi
  imul   $0x6667,%edx,%edx
  sar    $0xf,%di
  sar    $0x12,%edx
  sub    %edi,%edx
  lea    (%rdx,%rdx,4),%edi
  add    %edi,%edi
  sub    %edi,%eax
L125:
  sub    $0x1,%rsi
  mov    %al,(%r9,%rcx,1)
  mov    %ecx,%eax
  add    $0x1,%rcx
  test   %si,%si
  js     L163
L170:
  movsbl 0x0(%rbp,%rsi,1),%eax
  sub    $0x30,%eax
  imul   %r8d,%eax
  add    %edx,%eax
  cmp    $0xa,%ax
  jne    L99
  xor    %eax,%eax
  mov    $0x1,%edx
  jmp    L125
  nopl   0x0(%rax,%rax,1)
L163:
  cmpw   $0xffff,0xe(%rsp)
  movswq %r15w,%rsi
  cmovge %r12,%rsi
  test   %dx,%dx
  je     L26
  mov    %dl,0x210(%rsp,%rsi,1)
  lea    0x2(%rax),%esi
L26:
  movswl %bx,%edi
  movswl %si,%esi
  add    %edi,%esi
  cmp    %esi,%edi
  jge    L155
  movslq %edi,%rcx
  xor    %r8d,%r8d
  nopw   0x0(%rax,%rax,1)
L74:
  movsbw 0x410(%rsp,%rcx,1),%dx
  mov    %ecx,%eax
  sub    %edi,%eax
  cltq
  movsbw 0x210(%rsp,%rax,1),%ax
  add    %edx,%eax
  lea    (%rax,%r8,1),%edx
  xor    %r8d,%r8d
  cmp    $0x9,%dx
  jle    L214
  sub    $0xa,%edx
  mov    $0x1,%r8d
L214:
  mov    %ebx,%eax
  add    $0x1,%ebx
  mov    %dl,0x410(%rsp,%rcx,1)
  movswq %bx,%rcx
  cmp    %esi,%ecx
  jl     L74
  test   %r8w,%r8w
  je     L155
  movb   $0x1,0x410(%rsp,%rcx,1)
  lea    0x2(%rax),%ebx
L155:
  sub    $0x1,%r10
  test   %r10w,%r10w
  jns    L100
L86:
  mov    %ebx,%edx
  xor    %ecx,%ecx
  sub    $0x1,%dx
  jns    L148
  jmp    L30
  nopw   0x0(%rax,%rax,1)
L33:
  mov    $0x30,%edi
  test   %cx,%cx
  je     L267
L246:
  call   <putchar@plt>
  mov    $0x1,%ecx
  lea    -0x1(%r12),%edx
  test   %r12w,%r12w
  je     L127
L148:
  movswq %dx,%rax
  mov    %edx,%r12d
  movzbl 0x410(%rsp,%rax,1),%eax
  test   %al,%al
  je     L33
L273:
  add    $0x30,%eax
  movsbl %al,%edi
  jmp    L246
L267:
  sub    $0x1,%r12d
  cmp    $0xffff,%r12w
  je     L30
  movswq %r12w,%rax
  movzbl 0x410(%rsp,%rax,1),%eax
  test   %al,%al
  jne    L273
  lea    -0x1(%r12),%edx
  test   %r12w,%r12w
  jne    L148
L127:
  test   %cx,%cx
  je     L30
L35:
  mov    $0xa,%edi
  call   <putchar@plt>
  mov    %rbp,%rdi
  call   <gets@plt>
  test   %rax,%rax
  jne    L168
L97:
  mov    0x608(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L251
  add    $0x618,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L30:
  mov    $0x30,%edi
  call   <putchar@plt>
  jmp    L35
L251:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
void main() {
  char a[251], b[251], m[502], ra[502];
  short la, lb, i, j, max, ml, ad, carry, lt, dif;
  while (gets(a)) {
    gets(b);
    la = strlen(a);
    lb = strlen(b);
    for (i = 0; i < la + lb; i++) {
      m[i] = 0;
      ra[i] = 0;
    }
    lt = 0;
    for (i = lb - 1; i >= 0; i--) {
      carry = 0;
      lt = 0;
      for (j = la - 1; j >= 0; j--) {
        ml = (b[i] - '0') * (a[j] - '0') + carry;
        if (ml == 10) {
          m[lt] = 0;
          carry = 1;
        } else {
          m[lt] = ml % 10;
          carry = ml / 10;
        }
        lt++;
      }
      if (carry) {
        m[lt++] = carry;
        carry = 0;
      }
      dif = lb - i - 1;
      for (j = dif; j < lt + dif; j++) {
        ad = ra[j] + m[j - dif] + carry;
        if (ad > 9) {
          ra[j] = ad - 10;
          carry = 1;
        } else {
          ra[j] = ad;
          carry = 0;
        }
      }
      if (carry)
        ra[j++] = carry;
    }
    lt = 0;
    for (i = j - 1; i >= 0; i--) {
      if (ra[i] != 0)
        lt = 1;
      if (lt)
        putchar(ra[i] + '0');
    }
    if (!lt)
      putchar('0');
    putchar('\n');
  }
}
```