public static void main ( String [ ] args ) {
  Scanner userInput = new Scanner ( System . in ) ;
  int n = userInput . nextInt ( ) ;
  int in [ ] = new int [ n ] ;
  ArrayList < Integer > out = new ArrayList < Integer > ( ) ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    in [ i ] = userInput . nextInt ( ) ;
  }
  for ( int i = n - 1 ;
  i >= 0 ;
  i -- ) {
    if ( out . contains ( in [ i ] ) ) continue ;
    out . add ( 0 , in [ i ] ) ;
  }
  System . out . println ( out . size ( ) ) ;
  for ( Integer integer : out ) {
    System . out . print ( integer + " " ) ;
  }
}

public static void main ( String [ ] args ) { Scanner userInput = new Scanner ( System . in ) ; int n = userInput . nextInt ( ) ; int in [ ] = new int [ n ] ; ArrayList < Integer > out = new ArrayList < Integer > ( ) ; for ( int i = 0 ; i < n ; i ++ ) { in [ i ] = userInput . nextInt ( ) ; } for ( int i = n - 1 ; i >= 0 ; i -- ) { if ( out . contains ( in [ i ] ) ) continue ; out . add ( 0 , in [ i ] ) ; } System . out . println ( out . size ( ) ) ; for ( Integer integer : out ) { System . out . print ( integer + " ▁ " ) ; } }
(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 (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)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) dimensions: (dimensions) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (local_variable_declaration type: (generic_type (type_identifier) (type_arguments (type_identifier))) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (generic_type (type_identifier) (type_arguments (type_identifier))) arguments: (argument_list)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (decimal_integer_literal)))) condition: (binary_expression left: (identifier) right: (decimal_integer_literal)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier))))) consequence: (continue_statement)) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (decimal_integer_literal) (array_access array: (identifier) index: (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))) (enhanced_for_statement type: (type_identifier) name: (identifier) value: (identifier) body: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (string_literal)))))))))