int dfs (vector <int> &g, int i , vector<bool> &vis)
{
    if (vis[i])
        return 0;

    vis[i] = true;
    return 1 + dfs (g,g[i],vis);

}
int main() {
    // [[0, 1], [1, 2], [3, 4]],
    vector <int> g = {1,2,2,4,4};
    vector <bool> vis (g.size()+1,false);
    int res = INT_MIN;
    for (int i = 0 ; i < g.size(); i ++)
    {
        if (!vis[i])
            res = max (res,dfs(g,i,vis));
    }
    cout<< res;
}