public static void main ( String [ ] args ) {
  Scanner scan = new Scanner ( System . in ) ;
  int n = scan . nextInt ( ) ;
  HashMap < Integer , Integer > mp = new HashMap < Integer , Integer > ( ) ;
  Set < Integer > set = new HashSet < Integer > ( ) ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    int m = scan . nextInt ( ) ;
    if ( set . contains ( m ) ) {
      if ( mp . containsKey ( m ) ) {
        int value = mp . get ( m ) ;
        mp . put ( m , value + 1 ) ;
      }
      else {
        mp . put ( m , 1 ) ;
      }
    }
    set . add ( m ) ;
  }
  int count = 0 ;
  for ( Entry < Integer , Integer > entry : mp . entrySet ( ) ) {
    Integer key = entry . getKey ( ) ;
    Integer value = entry . getValue ( ) ;
    if ( value % 2 == 1 ) {
      count ++ ;
    }
  }
  System . out . println ( set . size ( ) - count ) ;
}

public static void main ( String [ ] args ) { Scanner scan = new Scanner ( System . in ) ; int n = scan . nextInt ( ) ; HashMap < Integer , Integer > mp = new HashMap < Integer , Integer > ( ) ; Set < Integer > set = new HashSet < Integer > ( ) ; for ( int i = 0 ; i < n ; i ++ ) { int m = scan . nextInt ( ) ; if ( set . contains ( m ) ) { if ( mp . containsKey ( m ) ) { int value = mp . get ( m ) ; mp . put ( m , value + 1 ) ; } else { mp . put ( m , 1 ) ; } } set . add ( m ) ; } int count = 0 ; for ( Entry < Integer , Integer > entry : mp . entrySet ( ) ) { Integer key = entry . getKey ( ) ; Integer value = entry . getValue ( ) ; if ( value % 2 == 1 ) { count ++ ; } } System . out . println ( set . size ( ) - count ) ; }
(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)))) (local_variable_declaration type: (generic_type (type_identifier) (type_arguments (type_identifier) (type_identifier))) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (generic_type (type_identifier) (type_arguments (type_identifier) (type_identifier))) arguments: (argument_list)))) (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)))) (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)))) (if_statement condition: (parenthesized_expression (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) consequence: (block (if_statement condition: (parenthesized_expression (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) consequence: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (binary_expression left: (identifier) right: (decimal_integer_literal)))))) alternative: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (decimal_integer_literal)))))))) (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))) (enhanced_for_statement type: (generic_type (type_identifier) (type_arguments (type_identifier) (type_identifier))) name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (decimal_integer_literal))) consequence: (block (expression_statement (update_expression (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (identifier)))))))