public static void main ( String [ ] args ) {
  Scanner s = new Scanner ( System . in ) ;
  int t = s . nextInt ( ) ;
  for ( int i = 0 ;
  i < t ;
  i ++ ) {
    int n = s . nextInt ( ) ;
    int a [ ] = new int [ n ] ;
    for ( int j = 0 ;
    j < n ;
    j ++ ) a [ j ] = s . nextInt ( ) ;
    Arrays . sort ( a ) ;
    int c [ ] = new int [ n ] ;
    int p = 0 ;
    for ( int g = n - 1 ;
    g >= 0 ;
    g -- ) {
      c [ p ] = a [ g ] ;
      p ++ ;
    }
    int b [ ] = new int [ n ] ;
    for ( int k = 0 ;
    k < n ;
    k ++ ) {
      b [ k ] = Math . min ( c [ k ] , ( k + 1 ) ) ;
    }
    int max = b [ 0 ] ;
    for ( int y = 0 ;
    y < n ;
    y ++ ) {
      if ( b [ y ] > max ) max = b [ y ] ;
    }
    System . out . println ( max ) ;
  }
}

public static void main ( String [ ] args ) { Scanner s = new Scanner ( System . in ) ; int t = s . nextInt ( ) ; for ( int i = 0 ; i < t ; i ++ ) { int n = s . nextInt ( ) ; int a [ ] = new int [ n ] ; for ( int j = 0 ; j < n ; j ++ ) a [ j ] = s . nextInt ( ) ; Arrays . sort ( a ) ; int c [ ] = new int [ n ] ; int p = 0 ; for ( int g = n - 1 ; g >= 0 ; g -- ) { c [ p ] = a [ g ] ; p ++ ; } int b [ ] = new int [ n ] ; for ( int k = 0 ; k < n ; k ++ ) { b [ k ] = Math . min ( c [ k ] , ( k + 1 ) ) ; } int max = b [ 0 ] ; for ( int y = 0 ; y < n ; y ++ ) { if ( b [ y ] > max ) max = b [ y ] ; } System . out . println ( max ) ; } }
(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)))) (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: (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))))) (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: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (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: (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))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) dimensions: (dimensions) 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 (array_access array: (identifier) index: (identifier)) (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (array_access array: (identifier) index: (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 (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (identifier))) consequence: (expression_statement (assignment_expression left: (identifier) right: (array_access array: (identifier) index: (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))))