public static void main ( String [ ] args ) {
  int n = sc . nextInt ( ) ;
  Button [ ] buttons = new Button [ n ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    buttons [ i ] = new Button ( sc . nextInt ( ) - 1 , false ) ;
  }
  buttons [ 0 ] . light = true ;
  int ans = - 1 ;
  int nowLight = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    buttons [ nowLight ] . light = false ;
    nowLight = buttons [ nowLight ] . Push ( ) ;
    buttons [ nowLight ] . light = true ;
    if ( nowLight == 1 ) {
      ans = i + 1 ;
      break ;
    }
  }
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) { int n = sc . nextInt ( ) ; Button [ ] buttons = new Button [ n ] ; for ( int i = 0 ; i < n ; i ++ ) { buttons [ i ] = new Button ( sc . nextInt ( ) - 1 , false ) ; } buttons [ 0 ] . light = true ; int ans = - 1 ; int nowLight = 0 ; for ( int i = 0 ; i < n ; i ++ ) { buttons [ nowLight ] . light = false ; nowLight = buttons [ nowLight ] . Push ( ) ; buttons [ nowLight ] . light = true ; if ( nowLight == 1 ) { ans = i + 1 ; break ; } } System . out . println ( ans ) ; }
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