void dfs(int u)
{
    int sz = g[u].size();
    for (int i = 0; i < sz; i ++)
    {
        int v = g[u][i];
        dfs(v);
        f[u] = f[u] > f[v] ? f[u] : f[v];
    }
    f[u] += sz;
}
int main()
{
    cin >> n;
    for (int i = 2; i <= n; i ++)
    {
        cin >> u;
        g[u].push_back(i);
    }
    dfs(1);
    cout << f[1];
    return 0;
}