import java.util.Arrays;

public class Main {
  private static void solve() {
    int n = ni();
    int[] par = new int[n];
    for (int i = 1; i < n; i ++) {
      par[i] = ni() - 1;
      
    }
    par[0] = -1;
    int[][] g = parentToG(par);
    System.out.println(dfs(0, -1, g));
  }
  
  public static int[][] parentToG(int[] par)
  {
      int n = par.length;
      int[] ct = new int[n];
      for(int i = 0;i < n;i++){
          if(par[i] >= 0){
              ct[i]++;
              ct[par[i]]++;
          }
      }
      int[][] g = new int[n][];
      for(int i = 0;i < n;i++){
          g[i] = new int[ct[i]];
      }
      for(int i = 0;i < n;i++){
          if(par[i] >= 0){
              g[par[i]][--ct[par[i]]] = i;
              g[i][--ct[i]] = par[i];
          }
      }
      return g;
  }
  
  private static int dfs(int now, int pre, int [][] g) {
    int cnt = g[now].length + (pre < 0 ? 0 : -1);
    int ptr = 0;
    int[] a = new int[cnt];
    for (int next : g[now]) {
      if (next == pre) {
        continue;
      }
      a[ptr ++] = dfs(next, now, g);
    }
    Arrays.sort(a);
    int ret = 0;
    for (int i = 0; i < ptr; i ++) {
      ret = Math.max(a[i] + (cnt - i), ret);
    }
    return ret;
  }
  public static void main(String[] args) {
    new Thread(null, new Runnable() {
      @Override
      public void run() {
        long start = System.currentTimeMillis();
        String debug = args.length > 0 ? args[0] : null;
        if (debug != null) {
          try {
            is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug));
          } catch (Exception e) {
            throw new RuntimeException(e);
          }
        }
        reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768);
        solve();
        out.flush();
        tr((System.currentTimeMillis() - start) + "ms");
      }
    }, "", 64000000).start();
  }

  private static java.io.InputStream is = System.in;
  private static java.io.PrintWriter out = new java.io.PrintWriter(System.out);
  private static java.util.StringTokenizer tokenizer = null;
  private static java.io.BufferedReader reader;

  public static String next() {
    while (tokenizer == null || !tokenizer.hasMoreTokens()) {
      try {
        tokenizer = new java.util.StringTokenizer(reader.readLine());
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }
    return tokenizer.nextToken();
  }

  private static double nd() {
    return Double.parseDouble(next());
  }

  private static long nl() {
    return Long.parseLong(next());
  }

  private static int[] na(int n) {
    int[] a = new int[n];
    for (int i = 0; i < n; i++)
      a[i] = ni();
    return a;
  }

  private static char[] ns() {
    return next().toCharArray();
  }

  private static long[] nal(int n) {
    long[] a = new long[n];
    for (int i = 0; i < n; i++)
      a[i] = nl();
    return a;
  }

  private static int[][] ntable(int n, int m) {
    int[][] table = new int[n][m];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[i][j] = ni();
      }
    }
    return table;
  }

  private static int[][] nlist(int n, int m) {
    int[][] table = new int[m][n];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[j][i] = ni();
      }
    }
    return table;
  }

  private static int ni() {
    return Integer.parseInt(next());
  }

  private static void tr(Object... o) {
    if (is != System.in)
      System.out.println(java.util.Arrays.deepToString(o));
  }
}


Measured memory_bytes: 57064