#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef LOCAL # include "debug_print.hpp" # define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__) #else # define debug(...) (static_cast(0)) #endif using namespace std; #define rep(i,n) for(int i=0; i<(n); i++) #define rrep(i,n) for(int i=(n)-1; i>=0; i--) #define FOR(i,a,b) for(int i=(a); i<(b); i++) #define RFOR(i,a,b) for(int i=(b-1); i>=(a); i--) #define ALL(v) v.begin(), v.end() #define RALL(v) v.rbegin(), v.rend() #define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() ); #define pb push_back using ll = long long; using D = double; using LD = long double; using P = pair; template using PQ = priority_queue>; template using minPQ = priority_queue, greater>; templatebool chmax(T &a, const T &b) { if (abool chmin(T &a, const T &b) { if (b ostream &operator<<(ostream &os, const pair &p) { os << p.first << " " << p.second; return os; } template istream &operator>>(istream &is, pair &p) { is >> p.first >> p.second; return is; } template ostream &operator<<(ostream &os, const vector &v) { int s = (int)v.size(); for (int i = 0; i < s; i++) os << (i ? " " : "") << v[i]; return os; } template istream &operator>>(istream &is, vector &v) { for (auto &x : v) is >> x; return is; } void in() {} template void in(T &t, U &...u) { cin >> t; in(u...); } void out() { cout << "\n"; } template void out(const T &t, const U &...u) { cout << t; if (sizeof...(u)) cout << sep; out(u...); } void outr() {} template void outr(const T &t, const U &...u) { cout << t; outr(u...); } template struct Fp { long long val; constexpr Fp(long long v = 0) noexcept : val(v % mod) { if (val < 0) val += mod; } constexpr int getmod() { return mod; } constexpr Fp operator - () const noexcept { return val ? mod - val : 0; } constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; } constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; } constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; } constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; } constexpr Fp& operator += (const Fp& r) noexcept { val += r.val; if (val >= mod) val -= mod; return *this; } constexpr Fp& operator -= (const Fp& r) noexcept { val -= r.val; if (val < 0) val += mod; return *this; } constexpr Fp& operator *= (const Fp& r) noexcept { val = val * r.val % mod; return *this; } constexpr Fp& operator /= (const Fp& r) noexcept { long long a = r.val, 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); } val = val * u % mod; if (val < 0) val += mod; return *this; } constexpr bool operator == (const Fp& r) const noexcept { return this->val == r.val; } constexpr bool operator != (const Fp& r) const noexcept { return this->val != r.val; } friend constexpr istream& operator >> (istream &is, const Fp& x) noexcept { int val; is >> val; x = Fp(val); return is; } friend constexpr ostream& operator << (ostream &os, const Fp& x) noexcept { return os << x.val; } friend constexpr Fp modpow(const Fp &a, long long n) noexcept { if (n == 0) return 1; auto t = modpow(a, n / 2); t = t * t; if (n & 1) t = t * a; return t; } }; //const int mod = 1e9+7; const int mod = 998244353; using mint = Fp; int main(){ ios_base::sync_with_stdio(false); cin.tie(nullptr); int n; in(n); vector> g(n); rep(i,n-1){ int a,b; in(a,b); a--; b--; g[a].pb(b); g[b].pb(a); } using PM = pair; vector> dp(n,vector(3)); auto calc1 = [] (vector &a, vector &b) -> mint{ if(b.size() > 1) return 0; if(b.size() == 1){ mint res = 1; for(auto [x,y] : a) res *= y; res *= b.front().first; return res; } mint pall = 1, chg = 0; for(auto [x,y] : a) pall *= y, chg += x/y; return pall * chg; }; auto calc2 = [] (vector &a, vector &b) -> mint{ if(b.size() > 2) return 0; if(b.size() == 2){ mint res = 1; for(auto [x,y] : a) res *= y; res *= b[0].first * b[1].first; return res; } if(b.size() == 1){ mint pall = 1, chg = 0; for(auto [x,y] : a) pall *= y, chg += x/y; return pall * chg * b[0].first; } mint zs_1 = 0, zs_2 = 0, yall = 1; for(auto [x,y] : a){ mint z = x/y; zs_1 += z; zs_2 += z*z; yall *= y; } return yall * (zs_1*zs_1-zs_2) / 2; }; auto dfs = [&] (auto dfs, int u, int p = -1) -> void{ vector a,b; mint res0 = 1; for(int v : g[u]){ if(v == p) continue; dfs(dfs,v,u); mint x = dp[v][0] + dp[v][1]; mint y = dp[v][2] + dp[v][1]; res0 *= y; if(y == 0) b.pb({x,y}); else a.pb({x,y}); } dp[u][0] = res0; dp[u][1] = calc1(a,b); dp[u][2] = calc2(a,b); }; dfs(dfs,0); out(dp[0][1]+dp[0][2]); }