public static void main ( String [ ] args ) {
  Scanner scanner = new Scanner ( System . in ) ;
  int totalButton = scanner . nextInt ( ) ;
  Integer [ ] buttonList = new Integer [ totalButton + 1 ] ;
  for ( int buttonNum = 0 ;
  buttonNum < totalButton ;
  buttonNum ++ ) {
    int temp = scanner . nextInt ( ) ;
    buttonList [ buttonNum + 1 ] = temp ;
  }
  int nowButton = 1 ;
  boolean flag = false ;
  int num ;
  for ( num = 0 ;
  num < totalButton ;
  num ++ ) {
    int temp = buttonList [ nowButton ] ;
    nowButton = temp ;
    if ( nowButton == 2 ) {
      flag = true ;
      num ++ ;
      break ;
    }
  }
  if ( flag == true ) {
    System . out . println ( num ) ;
  }
  else {
    System . out . println ( "-1" ) ;
  }
}

public static void main ( String [ ] args ) { Scanner scanner = new Scanner ( System . in ) ; int totalButton = scanner . nextInt ( ) ; Integer [ ] buttonList = new Integer [ totalButton + 1 ] ; for ( int buttonNum = 0 ; buttonNum < totalButton ; buttonNum ++ ) { int temp = scanner . nextInt ( ) ; buttonList [ buttonNum + 1 ] = temp ; } int nowButton = 1 ; boolean flag = false ; int num ; for ( num = 0 ; num < totalButton ; num ++ ) { int temp = buttonList [ nowButton ] ; nowButton = temp ; if ( nowButton == 2 ) { flag = true ; num ++ ; break ; } } if ( flag == true ) { System . out . println ( num ) ; } else { System . out . println ( " - 1" ) ; } }
(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: (array_type element: (type_identifier) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (type_identifier) dimensions: (dimensions_expr (binary_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: (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)))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (identifier))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (boolean_type) declarator: (variable_declarator name: (identifier) value: (false))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier))) (for_statement init: (assignment_expression left: (identifier) right: (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: (array_access array: (identifier) index: (identifier)))) (expression_statement (assignment_expression left: (identifier) right: (identifier))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (true))) (expression_statement (update_expression (identifier))) (break_statement))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (true))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))) alternative: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal))))))))