public static void main ( String [ ] args ) throws IOException {
  BufferedReader input = new BufferedReader ( new InputStreamReader ( System . in ) ) ;
  int n = Integer . parseInt ( input . readLine ( ) ) ;
  int [ ] positions = new int [ n + 1 ] ;
  int currentIndex = 1 ;
  for ( int i = 1 ;
  i <= n ;
  i ++ ) {
    positions [ i ] = Integer . parseInt ( input . readLine ( ) ) ;
  }
  int count = 0 ;
  while ( currentIndex != 2 && positions [ currentIndex ] > 0 ) {
    int copyCurrentIndex = currentIndex ;
    currentIndex = positions [ currentIndex ] ;
    positions [ copyCurrentIndex ] = - 1 ;
    count ++ ;
  }
  System . out . println ( currentIndex == 2 ? count : - 1 ) ;
}

public static void main ( String [ ] args ) throws IOException { BufferedReader input = new BufferedReader ( new InputStreamReader ( System . in ) ) ; int n = Integer . parseInt ( input . readLine ( ) ) ; int [ ] positions = new int [ n + 1 ] ; int currentIndex = 1 ; for ( int i = 1 ; i <= n ; i ++ ) { positions [ i ] = Integer . parseInt ( input . readLine ( ) ) ; } int count = 0 ; while ( currentIndex != 2 && positions [ currentIndex ] > 0 ) { int copyCurrentIndex = currentIndex ; currentIndex = positions [ currentIndex ] ; positions [ copyCurrentIndex ] = - 1 ; count ++ ; } System . out . println ( currentIndex == 2 ? count : - 1 ) ; }
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