#include <iostream>
#include <string>

using namespace std;

struct Link
{ string data;
  Link * next;
  Link(string d, Link * n); };

struct List
{ Link * first, * last;
  List();
  void insert(string s);
  void add_at_end(string s);
  void add_all_to_end(List x);
  void printall();
  bool not_empty();
  string remove_first();
  void split(List & x); };

Link::Link(string d, Link * n)
{ data = d;
  next = n; }

List::List()
{ first = NULL;
  last = NULL; }

void List::insert(string s)
{ first = new Link(s, first);
  if (last == NULL)
    last = first; }

void List::add_at_end(string s)
{ if (first == NULL)
  { first = new Link(s, first);
    last = first; }
  else
  { last->next = new Link(s, NULL);
    last = last->next; } }

void List::add_all_to_end(List x)
{ if (first == NULL)
  { first = x.first;
    last = x.last; }
  else
  { last->next = x.first;
    if (x.last != NULL)
      last = x.last; } }

bool List::not_empty()
{ return first != NULL; }

string List::remove_first()
{ if (first == NULL)
  { cerr << "Removing from empty list\n";
    exit(1); }
  string s = first->data;
  first = first->next;
  if (first == NULL)
    last = NULL;
  return s; }

void List::printall()
{ Link * ptr = first;
  while (ptr != NULL)
  { cout << ptr->data << " ";
    ptr = ptr->next; }
  if (last == NULL)
    cout << "(last=NULL)\n";
  else
    cout << "(last=" << last->data << ")\n"; }

void List::split(List & x)
{ Link * ptr1 = first, * ptr2 = first, * prev2 = NULL;
  while (true)
  { if (ptr1 == NULL)
      break;
    ptr1 = ptr1->next;
    if (ptr2 == NULL)
      break;
    prev2 = ptr2;
    ptr2 = ptr2->next;
    if (ptr1 == NULL)
      break;
    ptr1 = ptr1->next; }
  if (prev2 == NULL)
  { x.first = NULL;
    x.last = NULL; }
  else
  { prev2->next = NULL;
    x.first = ptr2;
    x.last = last;
    last = prev2; }
  if (x.first == NULL)
    x.last = NULL; }

List merge(List a, List b)
{ List r;
  while (a.not_empty() && b.not_empty())
  { string x;
    if (a.first->data < b.first->data)
      x = a.remove_first();
    else
      x = b.remove_first();
    r.add_at_end(x); }
  if (a.not_empty())
    r.add_all_to_end(a);
  else
    r.add_all_to_end(b);
  return r; }

int main()
{ List a, b;
  while (true)
  { string s;
    cin >> s;
    if (s == "****")
      break;
    a.add_at_end(s); }
  while (true)
  { string s;
    cin >> s;
    if (s == "****")
      break;
    b.add_at_end(s); }

  List c = merge(a, b);

  cout << "a: ";
  a.printall();
  cout << "b: ";
  b.printall();
  cout << "c: ";
  c.printall(); }