vector adj[maxN];

vectordist;

void dfs(int u , int p)

{

for (auto v : adj[u])

{

    if (v == p) continue;

    dist[v] = dist[u] + 1;

    dfs(v , u);

}

}

void solve()

{

int n ; cin >> n;

for (int i = 0 ; i < n ; i++) adj[i].clear();

for (int i = 0 ; i < n - 1 ; i++)

{

    int u , v ; cin >> u >> v;

    u--; v--;


    adj[u].push_back(v);

    adj[v].push_back(u);

}

if (n == 1)

{

    cout << 3 << endl;


    return;

}

dist.assign(n , 0);

dfs(0 , -1);

int u = max_element(all(dist)) - dist.begin();

dist.assign(n , 0);

dfs(u , -1);

int v = max_element(all(dist)) - dist.begin();

int max_d = *max_element(all(dist));


set<int>st1 , st2;

for (int i = 0 ; i < n ; i++)


{



    if (i == u)continue;

    if (dist[i] == max_d)st1.insert(i);

    if (dist[i] == max_d - 1)st2.insert(i);


}

dist.assign(n , 0);

dfs(v , -1);

for (int i = 0 ; i < n ; i++)

{

    if (i == v)continue;

    if (dist[i] == max_d)st1.insert(i);

    if (dist[i] == max_d - 1)st2.insert(i);

}

int ans = 2 * st2.size();

ans += (2 * (max_d) * st1.size());

int x = st1.size();

ans += (x * (x - 1));

ans += x;

cout << ans << endl;

}