//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx")
//#undef LOCAL




#include <algorithm>

#include <array>

#include <bitset>

#include <cassert>

#include <complex>

#include <cstdio>

#include <cstring>

#include <iostream>

#include <map>

#include <numeric>

#include <queue>

#include <set>

#include <string>

#include <unordered_map>

#include <unordered_set>

#include <vector>

using namespace std;

using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n - 1); }
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;

struct Scanner {
    FILE* fp = nullptr;
    char line[(1 << 15) + 1];
    size_t st = 0, ed = 0;
    void reread() {
        memmove(line, line + st, ed - st);
        ed -= st;
        st = 0;
        ed += fread(line + ed, 1, (1 << 15) - ed, fp);
        line[ed] = '\0';
    }
    bool succ() {
        while (true) {
            if (st == ed) {
                reread();
                if (st == ed) return false;
            }
            while (st != ed && isspace(line[st])) st++;
            if (st != ed) break;
        }
        if (ed - st <= 50) reread();
        return true;
    }
    template <class T, enable_if_t<is_same<T, string>::value, int> = 0>
    bool read_single(T& ref) {
        if (!succ()) return false;
        while (true) {
            size_t sz = 0;
            while (st + sz < ed && !isspace(line[st + sz])) sz++;
            ref.append(line + st, sz);
            st += sz;
            if (!sz || st != ed) break;
            reread();
        }
        return true;
    }
    template <class T, enable_if_t<is_integral<T>::value, int> = 0>
    bool read_single(T& ref) {
        if (!succ()) return false;
        bool neg = false;
        if (line[st] == '-') {
            neg = true;
            st++;
        }
        ref = T(0);
        while (isdigit(line[st])) {
            ref = 10 * ref + (line[st++] - '0');
        }
        if (neg) ref = -ref;
        return true;
    }
    template <class T> bool read_single(V<T>& ref) {
        for (auto& d : ref) {
            if (!read_single(d)) return false;
        }
        return true;
    }
    void read() {}
    template <class H, class... T> void read(H& h, T&... t) {
        bool f = read_single(h);
        assert(f);
        read(t...);
    }
    Scanner(FILE* _fp) : fp(_fp) {}
};

struct Printer {
  public:
    template <bool F = false> void write() {}
    template <bool F = false, class H, class... T>
    void write(const H& h, const T&... t) {
        if (F) write_single(' ');
        write_single(h);
        write<true>(t...);
    }
    template <class... T> void writeln(const T&... t) {
        write(t...);
        write_single('\n');
    }

    Printer(FILE* _fp) : fp(_fp) {}
    ~Printer() { flush(); }

  private:
    static constexpr size_t SIZE = 1 << 15;
    FILE* fp;
    char line[SIZE], small[50];
    size_t pos = 0;
    void flush() {
        fwrite(line, 1, pos, fp);
        pos = 0;
    }
    void write_single(const char& val) {
        if (pos == SIZE) flush();
        line[pos++] = val;
    }
    template <class T, enable_if_t<is_integral<T>::value, int> = 0>
    void write_single(T val) {
        if (pos > (1 << 15) - 50) flush();
        if (val == 0) {
            write_single('0');
            return;
        }
        if (val < 0) {
            write_single('-');
            val = -val; // todo min
        }
        size_t len = 0;
        while (val) {
            small[len++] = char('0' + (val % 10));
            val /= 10;
        }
        for (size_t i = 0; i < len; i++) {
            line[pos + i] = small[len - 1 - i];
        }
        pos += len;
    }
    void write_single(const string& s) {
        for (char c : s) write_single(c);
    }
    void write_single(const char* s) {
        size_t len = strlen(s);
        for (size_t i = 0; i < len; i++) write_single(s[i]);
    }
    template <class T> void write_single(const V<T>& val) {
        auto n = val.size();
        for (size_t i = 0; i < n; i++) {
            if (i) write_single(' ');
            write_single(val[i]);
        }
    }
};


template <uint MD> struct ModInt {
    using M = ModInt;
    static constexpr uint get_mod() { return MD; }
    const static M G;
    uint v;
    ModInt(ll _v = 0) { set_v(uint(_v % MD + MD)); }
    M& set_v(uint _v) {
        v = (_v < MD) ? _v : _v - MD;
        return *this;
    }
    explicit operator bool() const { return v != 0; }
    M operator-() const { return M() - *this; }
    M operator+(const M& r) const { return M().set_v(v + r.v); }
    M operator-(const M& r) const { return M().set_v(v + MD - r.v); }
    M operator*(const M& r) const { return M().set_v(uint(ull(v) * r.v % MD)); }
    M operator/(const M& r) const { return *this * r.inv(); }
    M& operator+=(const M& r) { return *this = *this + r; }
    M& operator-=(const M& r) { return *this = *this - r; }
    M& operator*=(const M& r) { return *this = *this * r; }
    M& operator/=(const M& r) { return *this = *this / r; }
    bool operator==(const M& r) const { return v == r.v; }
    M pow(ll n) const {
        M x = *this, r = 1;
        while (n) {
            if (n & 1) r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    M inv() const { return pow(MD - 2); }
    friend ostream& operator<<(ostream& os, const M& r) { return os << r.v; }
};
// using Mint = ModInt<998244353>;
// template<> const Mint Mint::G = Mint(3);

using Mint = ModInt<998244353>;

Scanner sc = Scanner(stdin);
Printer pr = Printer(stdout);

VV<int> g;

int mdp, mv;
void dfs(int p, int b, int ndp = 0) {
    if (mdp <= ndp) {
        mdp = ndp;
        mv = p;
    }
    for (int d: g[p]) {
        if (d == b) continue;
        dfs(d, p, ndp + 1);
    }
}

V<int> path;
bool dfs_path(int p, int b, int t) {
    if (p == t) {
        path.push_back(p);
        return true;
    }
    for (int d: g[p]) {
        if (d == b) continue;
        if (dfs_path(d, p, t)) {
            path.push_back(p);
            return true;
        }
    }
    return false;
}

int U;

using P = array<Mint, 3>;

P solve(int p, int b, int ndps = 0) {
    if (g[p].size() == 1) {
        // leaf
        if (ndps == U) {
            // rad
            return {Mint(2), Mint(1), Mint(0)};
        } else {
//            dbg(p, b, P{Mint(3), Mint(0)});
            return {Mint(3), Mint(0), Mint(0)};
        }
    }
    P dp = {Mint(1), Mint(0), Mint(0)};
    for (auto d: g[p]) {
        if (d == b) continue;
        auto ch = solve(d, p, ndps + 1);
        P ndp = {Mint(0), Mint(0), Mint(0)};
        for (int a = 0; a < 3; a++) {
            for (int b = 0; b < 3; b++) {
                ndp[min(2, a + b)] += dp[a] * ch[b];
            }
        }
        dp = ndp;
    }
    dp[0] = dp[0] * Mint(3) + (dp[1] + dp[2]) * Mint(2);
    return dp;
}

int main() {
    int n;
    sc.read(n);
    g = VV<int>(n);
    for (int i = 0; i < n - 1; i++) {
        int a, b;
        sc.read(a, b); a--; b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    dfs(0, -1);
    int u = mv;
    dfs(mv, -1);
    int v = mv;
    dfs_path(u, -1, v);

    int L = int(path.size());
    if (L % 2) {
        U = (L / 2) - 1;
        int mid = path[L / 2];
                       ;
        V<Mint> dp(4);
        dp[0] = Mint(1);
        for (int d: g[mid]) {
            V<Mint> ndp(4);
            auto x = solve(d, mid);
            Mint x0 = x[0] - (x[1] + x[2]), x1 = x[1];
            ndp[3] = dp[3] * x0 + dp[2] * x1 + dp[1] * x1;
            ndp[2] = dp[2] * x0 + dp[0] * x1;
            ndp[1] = dp[1] * x0 + dp[0] * x1;
            ndp[0] = dp[0] * x0;
            dp = ndp;
        }
               ;
        pr.writeln((dp[3] / Mint(2)).v);
    } else {
        int mid0 = path[L / 2 - 1], mid1 = path[L / 2];
        U = (L / 2 - 1);
        auto x = solve(mid0, mid1);
        auto y = solve(mid1, mid0);
        pr.writeln((x[1] * y[1]).v);
    }
    return 0;
}


Measured memory_bytes: 18940