public static void main ( String [ ] args ) {
  Scanner in = new Scanner ( new BufferedReader ( new InputStreamReader ( System . in ) ) ) ;
  PrintWriter out = new PrintWriter ( new BufferedWriter ( new OutputStreamWriter ( System . out ) ) ) ;
  int n = in . nextInt ( ) , k = in . nextInt ( ) ;
  out . print ( ( k + 1 ) + " " ) ;
  for ( int i = 1 ;
  i <= 2 * n ;
  i ++ ) if ( i != k + 1 ) out . print ( i + " " ) ;
  out . flush ( ) ;
  out . close ( ) ;
  in . close ( ) ;
}

public static void main ( String [ ] args ) { Scanner in = new Scanner ( new BufferedReader ( new InputStreamReader ( System . in ) ) ) ; PrintWriter out = new PrintWriter ( new BufferedWriter ( new OutputStreamWriter ( System . out ) ) ) ; int n = in . nextInt ( ) , k = in . nextInt ( ) ; out . print ( ( k + 1 ) + " ▁ " ) ; for ( int i = 1 ; i <= 2 * n ; i ++ ) if ( i != k + 1 ) out . print ( i + " ▁ " ) ; out . flush ( ) ; out . close ( ) ; in . close ( ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (object_creation_expression type: (type_identifier) arguments: (argument_list (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))))))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (object_creation_expression type: (type_identifier) arguments: (argument_list (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (string_literal))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (binary_expression left: (decimal_integer_literal) right: (identifier))) update: (update_expression (identifier)) body: (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (string_literal))))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))