public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  String s1 = sc . next ( ) ;
  char [ ] a = s1 . toCharArray ( ) ;
  int len = a . length ;
  HashSet < Character > set = new HashSet < Character > ( ) ;
  int count = 0 ;
  for ( int i = 0 ;
  i < len ;
  i ++ ) {
    if ( ! set . contains ( a [ i ] ) ) {
      set . add ( a [ i ] ) ;
      count ++ ;
    }
  };
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; String s1 = sc . next ( ) ; char [ ] a = s1 . toCharArray ( ) ; int len = a . length ; HashSet < Character > set = new HashSet < Character > ( ) ; int count = 0 ; for ( int i = 0 ; i < len ; i ++ ) { if ( ! set . contains ( a [ i ] ) ) { set . add ( a [ i ] ) ; 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: (type_identifier) 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: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (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 (type_identifier))) arguments: (argument_list)))) (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: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (unary_expression operand: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier)))))) consequence: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier))))) (expression_statement (update_expression (identifier)))))))))