#include <atcoder/modint.hpp>
#include <bits/stdc++.h>
#include <numeric>
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 mint = atcoder::modint998244353;
int main() {
  int 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);
  }
  auto bfs = [&](int v, vi &dist) {
    queue<int> bfs;
    dist[v] = 0;
    bfs.push(v);
    while (bfs.size()) {
      int v = bfs.front();
      bfs.pop();
      for (int u : G[v]) {
        if (dist[u] > dist[v] + 1) {
          dist[u] = dist[v] + 1;
          bfs.push(u);
        }
      }
    }
  };
  vi dist0(N, INF), dist(N, INF);
  bfs(0, dist0);
  int d1 = max_element(all(dist0)) - begin(dist0);
  bfs(d1, dist);
  int d2 = max_element(all(dist)) - begin(dist);
  vi used(N);
  auto dfs = [&](auto f, int v, int p) -> int {
    int ret = 0;
    for (int u : G[v]) {
      if (u != p)
        chmax(ret, f(f, u, v));
    }
    return ret + 1;
  };
  int diam = dist[d2], cnt = 0, K = 0;
  using ai3 = array<int, 3>;
  ai3 depth{0, 0, 0};
  do {
    if (sz(G[d2]) > 1) {
      vi d;
      d.push_back(diam - cnt);
      d.push_back(cnt);
      d.push_back(0);
      for (int v : G[d2]) {
        if (dist[v] < dist[d2])
          continue;
        if (used[v])
          continue;
        d.push_back(dfs(dfs, v, d2));
      }
      sort(all(d));
      reverse(all(d));
      ai3 now{d[0], d[1], d[2]};
      if (d[0] + d[1] + d[2] > K) {
        depth = now;
        K = d[0] + d[1] + d[2];
      } else if (d[0] + d[1] + d[2] == K) {
        chmin(depth, now);
      }
    }
    used[d2] = 1;
    for (int v : G[d2]) {
      if (dist[v] < dist[d2]) {
        d2 = v;
        break;
      }
    }
    cnt++;
  } while (d1 != d2);
  mint ans = mint(2).pow(N + 2);
  ans -= mint(2).pow(N - K - 1) *
         (mint(2).pow(depth[0] + 2) + mint(2).pow(depth[1] + 2) +
          mint(2).pow(depth[2] + 2) - 6);
  cout << ans.val() << '\n';
}