#define ATCODER #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using ll = long long; #define FOR(i, a, b) for(ll i=(a); i<(b);i++) #define REP(i, n) for(ll i=0; i<(n);i++) #define ROF(i, a, b) for(ll i=(b-1); i>=(a);i--) #define PER(i, n) for(ll i=n-1; i>=0;i--) #define VL vector #define VVL vector> #define VP vector< pair > #define VVP vector>> #define all(i) begin(i),end(i) #define SORT(i) sort(all(i)) #define EXISTBIT(x,i) (((x>>i) & 1) != 0) #define MP(a,b) make_pair(a,b) #ifdef ATCODER #include using namespace atcoder; using mint = modint1000000007; using mint2 = modint998244353; #endif template vector read(size_t n) { vector ts(n); for (size_t i = 0; i < n; i++) cin >> ts[i]; return ts; } template void read_tuple_impl(TV&) {} template void read_tuple_impl(TV& ts) { get(ts).emplace_back(*(istream_iterator(cin))); read_tuple_impl(ts); } template decltype(auto) read_tuple(size_t n) { tuple...> ts; for (size_t i = 0; i < n; i++) read_tuple_impl(ts); return ts; } template T det2(array ar) { return ar[0] * ar[3] - ar[1] * ar[2]; } template T det3(array ar) { return ar[0] * ar[4] * ar[8] + ar[1] * ar[5] * ar[6] + ar[2] * ar[3] * ar[7] - ar[0] * ar[5] * ar[7] - ar[1] * ar[3] * ar[8] - ar[2] * ar[4] * ar[6]; } template bool chmax(T& tar, T src) { return tar < src ? tar = src, true : false; } template bool chmin(T& tar, T src) { return tar > src ? tar = src, true : false; } template void inc(vector& ar) { for (auto& v : ar) v++; } template void dec(vector& ar) { for (auto& v : ar) v--; } template vector> id_sort(vector& a) { vector res(a.size()); for (int i = 0; i < a.size(); i++)res[i] = MP(a[i], i); SORT(res); return res; } using val = ll; using func = ll; val op(val a, val b) { return a ^ b; } val e() { return 0; } //val mp(func f, val a) { return MP(a.first + f * a.second, a.second); } //func comp(func f, func g) { return f + g; } //func id() { return 0; } // Rook ll dxr[4] = { 1,0,-1,0 }; ll dyr[4] = { 0,1,0,-1 }; // Bishop ll dxb[4] = { -1,-1,1,1 }; ll djb[4] = { -1,1,-1,1 }; // qween ll dxq[8] = { 0,-1,-1,-1,0,1,1,1 }; ll dyq[8] = { -1,-1,0,1,1,1,0,-1 }; void solve() { ll n; cin >> n; vector g(n); REP(i, n - 1) { ll u, v; cin >> u >> v; u--; v--; g[u].emplace_back(v, ll(g[v].size())); g[v].emplace_back(u, ll(g[u].size()) - 1); } VL li(n, 0), ri(n, -1); VVL ls(n), rs(n); REP(i, n) { ri[i] = g[i].size() - 1; ls[i].resize(g[i].size() + 1); rs[i].resize(g[i].size() + 1); } VVL ss(n); auto dfs = [&](auto self, ll now, ll parent, ll pi) -> ll { ll res = 0; if (pi == -1)pi = g[now].size(); while (li[now] < pi) { auto [vv, ii] = g[now][li[now]]; ll r = self(self, vv, now, ii); ls[now][li[now] + 1] = max(r, ls[now][li[now]]); ss[now].push_back(r); li[now]++; } while (ri[now] > pi) { auto [vv, ii] = g[now][ri[now]]; ll r = self(self, vv, now, ii); rs[now][ri[now] - 1] = max(r, rs[now][ri[now]]); ri[now]--; } return max(ls[now][pi], rs[now][pi]) + 1; }; ll ans = 0; REP(i, n) { dfs(dfs, i, -1, -1); SORT(ss[i]); reverse(all(ss[i])); REP(j, ss[i].size()) { chmax(ans, (j + 1) * ss[i][j]); } } cout << ans + 1; } int main() { ll t = 1; // cin >> t; while (t--) { solve(); } return 0; }