public static void main ( String [ ] args ) {
  FastReader fs = new FastReader ( ) ;
  String n = fs . nextLine ( ) ;
  long result , counter = 0 ;
  while ( n . length ( ) > 1 ) {
    counter ++ ;
    result = 0 ;
    for ( int i = 0 ;
    i < n . length ( ) ;
    i ++ ) {
      result += Integer . parseInt ( Character . toString ( n . charAt ( i ) ) ) ;
    }
    n = String . valueOf ( result ) ;
  }
  System . out . println ( counter ) ;
}

public static void main ( String [ ] args ) { FastReader fs = new FastReader ( ) ; String n = fs . nextLine ( ) ; long result , counter = 0 ; while ( n . length ( ) > 1 ) { counter ++ ; result = 0 ; for ( int i = 0 ; i < n . length ( ) ; i ++ ) { result += Integer . parseInt ( Character . toString ( n . charAt ( i ) ) ) ; } n = String . valueOf ( result ) ; } System . out . println ( counter ) ; }
(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)))) (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: (integral_type) declarator: (variable_declarator name: (identifier)) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (while_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal))) body: (block (expression_statement (update_expression (identifier))) (expression_statement (assignment_expression left: (identifier) right: (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: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))))))))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))