#include <iostream>
#include <string>
#include <algorithm>
#include <utility>
#include <cmath>
#include <cstdlib>
#include <map>
#include <set>
#include <queue>
#include <vector>
#include "testlib.h"
using namespace std;
using Graph = vector<vector<int>>;
#define MOD 998244353

vector<long long> depth;
vector<long long> subtree_size;
vector<bool> seen;
void dfs(const Graph& G, int v, int p, int d) {
    seen[v] = true;
    depth[v] = d;
    for (auto nv : G[v]) {
        if (nv == p) continue;
        dfs(G, nv, v, d + 1);
    }

    subtree_size[v] = 1;
    for (auto c : G[v]) {
        if (c == p) continue;
        subtree_size[v] += subtree_size[c];
    }
}

long long modinv(long long a, long long mod) {
    long long b = mod, u = 1, v = 0;
    while (b) {
        long long t = a / b;
        a -= t * b; swap(a, b);
        u -= t * v; swap(u, v);
    }
    u %= mod;
    if (u < 0) u += mod;
    return u;
}

int main() {
    registerValidation();
    long long N = inf.readLong((long long)2, (long long)100000);
    inf.readEoln();

    Graph G(N);
    for (int i = 0; i < N - 1; i++) {
        int a = inf.readLong((long long)1, N);
        inf.readSpace();
        int b = inf.readLong((long long)1, N);
        inf.readEoln();
        G[a - 1].push_back(b - 1);
        G[b - 1].push_back(a - 1);
    }
    inf.readEof();

    depth.assign(N, 0);
    subtree_size.assign(N, 0);
    seen.assign(N, false);

    dfs(G, 0, -1, 0);

    bool flag = false;
    for (int i = 0; i < N; i++) if (seen[i] == false) flag = true;
    if (flag) cout << -1 << endl;

    long long sum = 0;
    for (int i = 1; i < N; i++) sum += (N * (N - 1) / 2 - subtree_size[i] * (N - subtree_size[i])) % MOD;

    sum = sum % MOD * modinv(N * (N - 1) / 2, MOD) % MOD * modinv(N - 1, MOD) % MOD;
    cout << sum << endl;
}