public static void main ( String [ ] args ) throws Exception {
  Scanner sc = new Scanner ( System . in ) ;
  int t = sc . nextInt ( ) ;
  while ( t -- > 0 ) {
    int n = sc . nextInt ( ) ;
    int [ ] a = new int [ 101 ] ;
    for ( int i = 0 ;
    i < n ;
    i ++ ) {
      a [ sc . nextInt ( ) ] ++ ;
    }
    int mexA = - 1 , mexB = - 1 ;
    for ( int i = 0 ;
    i < a . length ;
    i ++ ) {
      if ( a [ i ] <= 1 && mexA == - 1 ) mexA = i ;
      if ( a [ i ] == 0 && mexB == - 1 ) mexB = i ;
    }
    System . out . println ( mexA + mexB ) ;
  }
}

public static void main ( String [ ] args ) throws Exception { Scanner sc = new Scanner ( System . in ) ; int t = sc . nextInt ( ) ; while ( t -- > 0 ) { int n = sc . nextInt ( ) ; int [ ] a = new int [ 101 ] ; for ( int i = 0 ; i < n ; i ++ ) { a [ sc . nextInt ( ) ] ++ ; } int mexA = - 1 , mexB = - 1 ; for ( int i = 0 ; i < a . length ; i ++ ) { if ( a [ i ] <= 1 && mexA == - 1 ) mexA = i ; if ( a [ i ] == 0 && mexB == - 1 ) mexB = i ; } System . out . println ( mexA + mexB ) ; } }
(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 (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)))) (while_statement condition: (parenthesized_expression (binary_expression left: (update_expression (identifier)) right: (decimal_integer_literal))) body: (block (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 (decimal_integer_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 (expression_statement (update_expression (array_access array: (identifier) index: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (unary_expression operand: (decimal_integer_literal))) declarator: (variable_declarator name: (identifier) value: (unary_expression operand: (decimal_integer_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: (field_access object: (identifier) field: (identifier))) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (unary_expression operand: (decimal_integer_literal))))) consequence: (expression_statement (assignment_expression left: (identifier) right: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (unary_expression operand: (decimal_integer_literal))))) consequence: (expression_statement (assignment_expression left: (identifier) right: (identifier)))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (identifier)))))))))