public static void main ( String [ ] args ) throws IOException {
  BufferedReader bf = new BufferedReader ( new InputStreamReader ( System . in ) ) ;
  int s = Integer . valueOf ( bf . readLine ( ) ) , m = 1 ;
  Set < Integer > number = new HashSet < > ( ) ;
  while ( true ) {
    if ( ! number . add ( s ) ) {
      break ;
    }
    if ( s % 2 > 0 ) {
      s = 3 * s + 1 ;
    }
    else {
      s /= 2 ;
    }
    m ++ ;
  }
  System . out . println ( m ) ;
}

public static void main ( String [ ] args ) throws IOException { BufferedReader bf = new BufferedReader ( new InputStreamReader ( System . in ) ) ; int s = Integer . valueOf ( bf . readLine ( ) ) , m = 1 ; Set < Integer > number = new HashSet < > ( ) ; while ( true ) { if ( ! number . add ( s ) ) { break ; } if ( s % 2 > 0 ) { s = 3 * s + 1 ; } else { s /= 2 ; } m ++ ; } System . out . println ( m ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) (throws (type_identifier)) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (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 (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (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)) arguments: (argument_list)))) (while_statement condition: (parenthesized_expression (true)) body: (block (if_statement condition: (parenthesized_expression (unary_expression operand: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))) consequence: (block (break_statement))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (binary_expression left: (decimal_integer_literal) right: (identifier)) right: (decimal_integer_literal))))) alternative: (block (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal))))) (expression_statement (update_expression (identifier))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))