public static void main ( String args [ ] ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = sc . nextInt ( ) ;
  int [ ] arr = new int [ n ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    arr [ i ] = sc . nextInt ( ) ;
  }
  LinkedHashSet h = new LinkedHashSet ( ) ;
  int [ ] arr1 = new int [ n ] ;
  int k = 0 ;
  for ( int i = n - 1 ;
  i >= 0 ;
  i -- ) {
    arr1 [ k ] = arr [ i ] ;
    k ++ ;
  }
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    if ( ! h . contains ( arr1 [ i ] ) ) h . add ( arr1 [ i ] ) ;
  }
  ArrayList < Integer > w = new ArrayList < Integer > ( h ) ;
  Collections . reverse ( w ) ;
  System . out . println ( w . size ( ) ) ;
  for ( int i : w ) System . out . print ( i + " " ) ;
}

public static void main ( String args [ ] ) { Scanner sc = new Scanner ( System . in ) ; int n = sc . nextInt ( ) ; int [ ] arr = new int [ n ] ; for ( int i = 0 ; i < n ; i ++ ) { arr [ i ] = sc . nextInt ( ) ; } LinkedHashSet h = new LinkedHashSet ( ) ; int [ ] arr1 = new int [ n ] ; int k = 0 ; for ( int i = n - 1 ; i >= 0 ; i -- ) { arr1 [ k ] = arr [ i ] ; k ++ ; } for ( int i = 0 ; i < n ; i ++ ) { if ( ! h . contains ( arr1 [ i ] ) ) h . add ( arr1 [ i ] ) ; } ArrayList < Integer > w = new ArrayList < Integer > ( h ) ; Collections . reverse ( w ) ; System . out . println ( w . size ( ) ) ; for ( int i : w ) System . out . print ( i + " ▁ " ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier) dimensions: (dimensions))) 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: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (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)))))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list)))) (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (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 (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (identifier)))) (expression_statement (update_expression (identifier))))) (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 (if_statement condition: (parenthesized_expression (unary_expression operand: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier)))))) consequence: (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (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 (identifier))))) (expression_statement (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 (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))) (enhanced_for_statement type: (integral_type) name: (identifier) value: (identifier) body: (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (string_literal))))))))