public static void main ( String args [ ] ) {
  Scanner sc = new Scanner ( System . in ) ;
  int t = sc . nextInt ( ) ;
  while ( t > 0 ) {
    int n , k ;
    n = sc . nextInt ( ) ;
    k = sc . nextInt ( ) ;
    int a [ ] = new int [ n ] ;
    int b [ ] = new int [ n ] ;
    for ( int i = 0 ;
    i < n ;
    i ++ ) {
      a [ i ] = sc . nextInt ( ) ;
    }
    for ( int i = 0 ;
    i < n ;
    i ++ ) {
      b [ i ] = sc . nextInt ( ) ;
    }
    Arrays . sort ( a ) ;
    Arrays . sort ( b ) ;
    int i = 0 , j = n - 1 , sum = 0 ;
    while ( k > 0 && b [ j ] > a [ i ] ) {
      sum += b [ j -- ] ;
      k -- ;
      i ++ ;
    }
    while ( i < n ) {
      sum += a [ i ++ ] ;
    }
    System . out . println ( sum ) ;
    t -- ;
  }
}

public static void main ( String args [ ] ) { Scanner sc = new Scanner ( System . in ) ; int t = sc . nextInt ( ) ; while ( t > 0 ) { int n , k ; n = sc . nextInt ( ) ; k = sc . nextInt ( ) ; int a [ ] = new int [ n ] ; int b [ ] = new int [ n ] ; for ( int i = 0 ; i < n ; i ++ ) { a [ i ] = sc . nextInt ( ) ; } for ( int i = 0 ; i < n ; i ++ ) { b [ i ] = sc . nextInt ( ) ; } Arrays . sort ( a ) ; Arrays . sort ( b ) ; int i = 0 , j = n - 1 , sum = 0 ; while ( k > 0 && b [ j ] > a [ i ] ) { sum += b [ j -- ] ; k -- ; i ++ ; } while ( i < n ) { sum += a [ i ++ ] ; } System . out . println ( sum ) ; t -- ; } }
(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)))) (while_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier)) declarator: (variable_declarator name: (identifier))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (assignment_expression left: (identifier) right: (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: (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)))))) (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)))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (decimal_integer_literal))) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (while_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (identifier))))) body: (block (expression_statement (assignment_expression left: (identifier) right: (array_access array: (identifier) index: (update_expression (identifier))))) (expression_statement (update_expression (identifier))) (expression_statement (update_expression (identifier))))) (while_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) body: (block (expression_statement (assignment_expression left: (identifier) right: (array_access array: (identifier) index: (update_expression (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier)))) (expression_statement (update_expression (identifier)))))))