public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  ArrayList < String > all_val = new ArrayList < > ( ) ;
  int big_loop = sc . nextInt ( ) ;
  for ( int loop = 0 ;
  loop < big_loop ;
  loop ++ ) {
    int num = sc . nextInt ( ) * 2 ;
    ArrayList < String > input = new ArrayList < > ( ) ;
    String ans = "" ;
    for ( int i = 0 ;
    i < num ;
    i ++ ) {
      String val = sc . nextInt ( ) + "" ;
      if ( input . contains ( val ) ) {
        ans += val + " " ;
      }
      else {
        input . add ( val ) ;
      }
    }
    all_val . add ( ans ) ;
  }
  for ( String an : all_val ) {
    System . out . println ( an ) ;
  }
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; ArrayList < String > all_val = new ArrayList < > ( ) ; int big_loop = sc . nextInt ( ) ; for ( int loop = 0 ; loop < big_loop ; loop ++ ) { int num = sc . nextInt ( ) * 2 ; ArrayList < String > input = new ArrayList < > ( ) ; String ans = " " ; for ( int i = 0 ; i < num ; i ++ ) { String val = sc . nextInt ( ) + " " ; if ( input . contains ( val ) ) { ans += val + " ▁ " ; } else { input . add ( val ) ; } } all_val . add ( ans ) ; } for ( String an : all_val ) { System . out . println ( an ) ; } }
(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: (generic_type (type_identifier) (type_arguments (type_identifier))) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (generic_type (type_identifier) (type_arguments)) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (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 (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)))) (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)) arguments: (argument_list)))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (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: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (string_literal)))) (if_statement condition: (parenthesized_expression (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (string_literal))))) alternative: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))))) (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 (identifier))))))))