list merge( a, b )
	list a, b;

	{
	list temp;
	struct rec aux;
	temp = &aux;
	while ( b != NULL )
		if ( a == NULL )	{ a = b;  break; }
		else	if ( b->k > a->k )
				{ temp = temp->next = a; a = a->next; }
			else	{ temp = temp->next = b; b = b->next; };
	temp->next = a;
	return( aux.next );
	};