public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int N = sc . nextInt ( ) ;
  int [ ] boss = new int [ N + 1 ] ;
  boss [ 0 ] = - 1 ;
  Map < Integer , List < Integer >> members = new HashMap < Integer , List < Integer >> ( ) ;
  for ( int i = 1 ;
  i <= N - 1 ;
  i ++ ) {
    int b = sc . nextInt ( ) ;
    boss [ i + 1 ] = b ;
    List < Integer > member = new ArrayList < Integer > ( ) ;
    if ( members . containsKey ( b ) ) {
      member = members . get ( b ) ;
    }
    member . add ( i + 1 ) ;
    members . put ( b , member ) ;
  }
  Queue < Integer > checkMember = new ArrayDeque < Integer > ( ) ;
  for ( int i = 1 ;
  i <= N ;
  i ++ ) {
    if ( ! members . containsKey ( i ) ) {
      checkMember . add ( i ) ;
    }
  }
  int [ ] salary = new int [ N + 1 ] ;
  while ( ! checkMember . isEmpty ( ) ) {
    int n = checkMember . poll ( ) ;
    if ( ! members . containsKey ( n ) ) {
      salary [ n ] = 1 ;
    }
    else {
      int max = Integer . MIN_VALUE ;
      int min = Integer . MAX_VALUE ;
      for ( Integer m : members . get ( n ) ) {
        max = Math . max ( max , salary [ m ] ) ;
        min = Math . min ( min , salary [ m ] ) ;
      }
      salary [ n ] = max + min + 1 ;
    }
    if ( ! checkMember . contains ( boss [ n ] ) && boss [ n ] != - 1 ) {
      checkMember . add ( boss [ n ] ) ;
    }
  }
  out . println ( salary [ 1 ] ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int N = sc . nextInt ( ) ; int [ ] boss = new int [ N + 1 ] ; boss [ 0 ] = - 1 ; Map < Integer , List < Integer > > members = new HashMap < Integer , List < Integer > > ( ) ; for ( int i = 1 ; i <= N - 1 ; i ++ ) { int b = sc . nextInt ( ) ; boss [ i + 1 ] = b ; List < Integer > member = new ArrayList < Integer > ( ) ; if ( members . containsKey ( b ) ) { member = members . get ( b ) ; } member . add ( i + 1 ) ; members . put ( b , member ) ; } Queue < Integer > checkMember = new ArrayDeque < Integer > ( ) ; for ( int i = 1 ; i <= N ; i ++ ) { if ( ! members . containsKey ( i ) ) { checkMember . add ( i ) ; } } int [ ] salary = new int [ N + 1 ] ; while ( ! checkMember . isEmpty ( ) ) { int n = checkMember . poll ( ) ; if ( ! members . containsKey ( n ) ) { salary [ n ] = 1 ; } else { int max = Integer . MIN_VALUE ; int min = Integer . MAX_VALUE ; for ( Integer m : members . get ( n ) ) { max = Math . max ( max , salary [ m ] ) ; min = Math . min ( min , salary [ m ] ) ; } salary [ n ] = max + min + 1 ; } if ( ! checkMember . contains ( boss [ n ] ) && boss [ n ] != - 1 ) { checkMember . add ( boss [ n ] ) ; } } out . println ( salary [ 1 ] ) ; }
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