#include <bits/stdc++.h>
using namespace std;
template <class F> class y_combinator {
    F f;

   public:
    y_combinator(F&& f) : f(std::forward<F>(f)) {}
    template <class... Args> auto operator()(Args&&... args) const { return f(*this, std::forward<Args>(args)...); }
};
using ll = long long;
using ld = long double;
template <class T, class U = std::less<T>> using prique = std::priority_queue<T, std::vector<T>, U>;
template <class T> T floor(T a, T b) noexcept { return a / b - (a % b && (a ^ b) < 0); }
template <class T> T ceil(T a, T b) noexcept { return floor(a + b - 1, b); }
template <class T> bool chmin(T& x, const T& y) noexcept { return (x > y ? x = y, true : false); }
template <class T> bool chmax(T& x, const T& y) noexcept { return (x < y ? x = y, true : false); }
#define overload4(a, b, c, d, e, ...) e
#define rep1(a) for (long long _i = 0; _i < (a); _i++)
#define rep2(i, a) for (long long i = 0; i < (a); i++)
#define rep3(i, a, b) for (long long i = (a); i < (b); i++)
#define rep4(i, a, b, c) for (long long i = (a); i < (b); i += (c))
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep(i, a, b, c) for (long long i = (a); i > (b); i += (c))
#define all(x) std::begin(x), std::end(x)
#define rall(x) std::rbegin(x), std::rend(x)
#define pb push_back
#ifndef LOCAL
#define debug(...)
#endif

void run_case() {
    int N;
    cin >> N;
    vector<vector<int>> G(N);
    rep(i, 1, N) {
        int a, b;
        cin >> a >> b;
        a--, b--;
        G[a].pb(b);
        G[b].pb(a);
    }
    vector<int> A(N), B(N);
    y_combinator([&](auto self, int v, int p = -1) -> void {
        A[v] = 1;
        for (int u : G[v])
            if (u != p) {
                self(u, v);
                chmax(A[v], A[u] + 1);
            }
    })(0);

    y_combinator([&](auto self, int v, int p = -1) -> void {
        vector<int> ch;
        for (int u : G[v])
            if (u != p) {
                ch.pb(A[u] + 1);
            }
        int mx1 = (ch.size() > 0 ? ch[0] : -1);
        int mx2 = (ch.size() > 0 ? ch[1] : -1);
        for (int u : G[v])
            if (u != p) {
                int t;
                if (A[u] + 1 == mx1) t = mx2;
                else t = mx1;
                chmax(B[u], max(t, B[v]) + 2);
                self(u, v);
            }
    })(0);
    int ans = 0;
    y_combinator([&](auto self, int v, int p = -1) -> void {
        vector<int> ch;
        for (int u : G[v]) {
            if (u == p) {
                ch.push_back(B[u]);
            } else {
                ch.push_back(A[u]);
            }
        }
        sort(rall(ch));
        rep(it, G[v].size()) {
            int val = ch[it];
            chmax<int>(ans, val * (it + 1) + 1);
        }
        for (int u : G[v])
            if (u != p) {
                self(u, v);
            }
    })(0);
    cout << ans << endl;
}

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::fixed(std::cout).precision(16);
    int T = 1;
    // cin >> T;
    while (T--) run_case();
    return 0;
}