#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; template struct modint { private: unsigned int value; static constexpr int mod() {return m;} public: constexpr modint(const long long x = 0) noexcept { long long y = x; if(y < 0 || y >= mod()) { y %= mod(); if(y < 0) y += mod(); } value = (unsigned int)y; } constexpr unsigned int val() noexcept {return value;} constexpr modint &operator+=(const modint &other) noexcept { value += other.value; if(value >= mod()) value -= mod(); return *this; } constexpr modint &operator-=(const modint &other) noexcept { unsigned int x = value; if(x < other.value) x += mod(); x -= other.value; value = x; return *this; } constexpr modint &operator*=(const modint &other) noexcept { unsigned long long x = value; x *= other.value; value = (unsigned int) (x % mod()); return *this; } constexpr modint &operator/=(const modint &other) noexcept { return *this *= other.inverse(); } constexpr modint inverse() const noexcept { assert(value); long long a = value,b = mod(),x = 1,y = 0; while(b) { long long q = a/b; a -= q*b; swap(a,b); x -= q*y; swap(x,y); } return modint(x); } constexpr modint power(long long N) const noexcept { assert(N >= 0); modint p = *this,ret = 1; while(N) { if(N & 1) ret *= p; p *= p; N >>= 1; } return ret; } constexpr modint operator+() {return *this;} constexpr modint operator-() {return modint() - *this;} constexpr modint &operator++(int) noexcept {return *this += 1;} constexpr modint &operator--(int) noexcept {return *this -= 1;} friend modint operator+(const modint& lhs, const modint& rhs) {return modint(lhs) += rhs;} friend modint operator-(const modint& lhs, const modint& rhs) {return modint(lhs) -= rhs;} friend modint operator*(const modint& lhs, const modint& rhs) {return modint(lhs) *= rhs;} friend modint operator/(const modint& lhs, const modint& rhs) {return modint(lhs) /= rhs;} friend ostream &operator<<(ostream &os,const modint &x) {return os << x.value;} }; using mint = modint<998244353>; /* using mint = modint<1000000007>; */ template struct combination { vector f,invf; combination(int N = 0) : f(1,1),invf(1,1) { update(N); } void update(int N) { if((int)f.size() > N) return; int pi = (int)f.size(); N = max(N,pi*2); f.resize(N+1),invf.resize(N+1); for(int i = pi;i <= N;i++) f[i] = f[i-1]*i; invf[N] = S(1)/f[N]; for(int i = N-1;i >= pi;i--) invf[i] = invf[i+1]*(i+1); } S factorial(int N) { update(N); return f[N]; } S invfactorial(int N) { update(N); return invf[N]; } S P(int N,int K) { assert(0 <= K && K <= N); update(N); return f[N]*invf[N-K]; } S C(int N,int K) { assert(0 <= K && K <= N); update(N); return f[N]*invf[K]*invf[N-K]; } S H(int N,int K) { if(!N) return K == 0 ? 1:0; return C(N+K-1,K); } }; combination C; void solve() { int N; cin >> N; vector> G(N); for(int i = 1;i < N;i++) { int u,v; cin >> u >> v; u--; v--; G[u].push_back(v); G[v].push_back(u); } vector ch(N); auto dfs = [&](auto dfs,int u,int p) -> void { ch[u] = 1; for(int v : G[u]) if(v != p) { dfs(dfs,v,u); ch[u] += ch[v]; } }; dfs(dfs,0,-1); vector A(N); for(int i = 0;i < N;i++) cin >> A[i]; mint ans = 0; for(int u = 0;u < N;u++) { vector P,Q; for(int v : G[u]) { if(ch[v] >= ch[u]) { if(A[v] > A[u]) P.push_back(N - ch[u]); else if(A[v] < A[u]) Q.push_back(N - ch[u]); } else { if(A[v] > A[u]) P.push_back(ch[v]); else if(A[v] < A[u]) Q.push_back(ch[v]); } } { mint S = 0; for(int i = 0;i < (int)P.size();i++) { ans += S * P[i]; S += P[i]; } } { mint S = 0; for(int i = 0;i < (int)Q.size();i++) { ans += S * Q[i]; S += Q[i]; } } } cout << ans << endl; } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int tt = 1; /* cin >> tt; */ while(tt--) solve(); }