public static void main ( String [ ] args ) throws IOException {
  BufferedReader input = new BufferedReader ( new InputStreamReader ( System . in ) ) ;
  String line = input . readLine ( ) ;
  int n = Integer . parseInt ( line ) ;
  System . out . println ( ( n % 2 == 0 ) ? n : n * 2 ) ;
}

public static void main ( String [ ] args ) throws IOException { BufferedReader input = new BufferedReader ( new InputStreamReader ( System . in ) ) ; String line = input . readLine ( ) ; int n = Integer . parseInt ( line ) ; System . out . println ( ( n % 2 == 0 ) ? n : n * 2 ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) (throws (type_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 (field_access object: (identifier) field: (identifier)))))))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (ternary_expression condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (decimal_integer_literal))) consequence: (identifier) alternative: (binary_expression left: (identifier) right: (decimal_integer_literal))))))))