//  比較関数が間違っている場合
#include <atcoder/modint.hpp>
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
#define rep3(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep2(i, a, b) rep3(i, a, b, 1)
#define rep1(i, n) rep2(i, 0, n)
#define rep0(n) rep1(aaaaa, n)
#define ov4(a, b, c, d, name, ...) name
#define rep(...) ov4(__VA_ARGS__, rep3, rep2, rep1, rep0)(__VA_ARGS__)
#define per(i, a, b) for (ll i = (a) - 1; i >= (b); i--)
#define fore(e, v) for (auto &&e : v)
#define all(a) begin(a), end(a)
#define sz(a) (int)(size(a))
#define lb(v, x) (lower_bound(all(v), x) - begin(v))
#define eb emplace_back

template <typename T, typename S> bool chmin(T &a, const S &b) {
  return a > b ? a = b, 1 : 0;
}
template <typename T, typename S> bool chmax(T &a, const S &b) {
  return a < b ? a = b, 1 : 0;
}
const int INF = 1e9 + 100;
const ll INFL = 3e18 + 100;
#define i128 __int128_t
struct _ {
  _() { cin.tie(0)->sync_with_stdio(0), cout.tie(0); }
} __;

using ai3 = array<int, 3>;
using ai5 = array<int, 5>;
using mint = atcoder::modint998244353;

// a<b ?
bool greater_check(ai3 a, ai3 b) {
  int ak = 0, bk = 0;
  rep(i, 3) ak += a[i];
  rep(i, 3) bk += b[i];
  if (ak > bk)
    return false;
  if (ak < bk)
    return true;
  return a > b;
}

int main() {
  ll N;
  cin >> N;
  vector<vi> G(N);
  rep(N - 1) {
    int U, V;
    cin >> U >> V;
    --U, --V;
    G[U].push_back(V);
    G[V].push_back(U);
  }
  unordered_map<ll, pii> edge_depth;
  auto dfs1 = [&](auto f, int v, int p) -> pii {
    pii ret{0, v};
    if (edge_depth.contains(v * N + p))
      return edge_depth[v * N + p];
    for (int u : G[v]) {
      if (u != p)
        chmax(ret, f(f, u, v));
    }
    ret.first++;
    return edge_depth[v * N + p] = ret;
  };
  dfs1(dfs1, 0, -1);
  auto dfs2 = [&](auto f, int v, int p) -> void {
    pii g1{0, v}, g2{-1, v};
    for (int u : G[v]) {
      if (edge_depth.contains(u * N + v)) {
        pii x = edge_depth[u * N + v];
        if (x > g1) {
          g2 = g1;
          g1 = x;
        } else if (x > g2) {
          g2 = x;
        }
      }
    }
    g1.first++, g2.first++;
    for (int u : G[v]) {
      if (u != p) {
        if (edge_depth[u * N + v].second == g1.second) {
          edge_depth[v * N + u] = g2;
        } else {
          edge_depth[v * N + u] = g1;
        }
        f(f, u, v);
      }
    }
  };
  dfs2(dfs2, 0, -1);
  ai3 ansd{-1, 0, 0};

  auto push3 = [](ai3 &x, int v) {
    if (v > x[0]) {
      x[2] = x[1], x[1] = x[0], x[0] = v;
    } else if (v > x[1]) {
      x[2] = x[1], x[1] = v;
    } else if (v > x[2]) {
      x[2] = v;
    }
  };
  rep(i, N) {
    ai3 now{0, 0, 0};
    for (int u : G[i]) {
      push3(now, edge_depth[u * N + i].first);
      // cerr<<edge_depth[u*N+i].first<<' '<<edge_depth[u*N+i].second<<'/';
    }
    // cerr<<endl;
    // for(auto i:now)cerr<<i<<' ';
    // cerr<<endl;
    if (ansd[0] == -1 || greater_check(ansd, now))
      ansd = now;
  }
  mint ans = mint(2).pow(N + 2);
  int K = 0;
  rep(i, 3) K += ansd[i];
  ans -= mint(2).pow(N - K - 1) *
         (mint(2).pow(ansd[0] + 2) + mint(2).pow(ansd[1] + 2) +
          mint(2).pow(ansd[2] + 2) - 6);
  cout << ans.val() << '\n';
}