#pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using namespace atcoder; typedef long long ll; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repr(i, n) for (int i = (int)(n)-1; i >= 0; i--) #define repk(i, k, n) for (int i = k; i < (int)(n); i++) #define all(v) v.begin(), v.end() #define mod1 1000000007 #define mod2 998244353 #define mod3 100000007 #define vi vector #define vs vector #define vc vector #define vl vector #define vb vector #define vvi vector> #define vvc vector> #define vvl vector> #define vvb vector> #define vvvi vector>> #define vvvl vector>> #define pii pair #define pil pair #define pli pair #define pll pair #define vpii vector> #define vpll vector> #define vvpii vector>> #define vvpll vector>> using mint = modint998244353; template void debug(T e) { cerr << e << endl; } template void debug(vector &v) { rep(i, v.size()) { cerr << v[i] << " "; } cerr << endl; } template void debug(vector> &v) { rep(i, v.size()) { rep(j, v[i].size()) { cerr << v[i][j] << " "; } cerr << endl; } } template void debug(vector> &v) { rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; } } template void debug(set &st) { for (auto itr = st.begin(); itr != st.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(multiset &ms) { for (auto itr = ms.begin(); itr != ms.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(map &mp) { for (auto itr = mp.begin(); itr != mp.end(); itr++) { cerr << itr->first << " " << itr->second << endl; } } void debug_out() { cerr << endl; } template void debug_out(Head H, Tail... T) { cerr << H << " "; debug_out(T...); } void dfs(vector> &graph, vector &isvisited, vector &prev, vector &dp, ll v) { isvisited[v] = true; ll dp_val = 1; for (ll i = 0; i < graph[v].size(); i++) { if (isvisited[graph[v][i]]) { continue; } prev[graph[v][i]] = v; dfs(graph, isvisited, prev, dp, graph[v][i]); dp_val += dp[graph[v][i]]; } dp[v] = dp_val; } int main() { ll N; cin >> N; vector U(N - 1); vector V(N - 1); for (ll i = 0; i < N - 1; i++) { cin >> U[i] >> V[i]; U[i]--; V[i]--; } vector> graph(N, vector(0)); for (ll i = 0; i < N - 1; i++) { graph[U[i]].push_back(V[i]); graph[V[i]].push_back(U[i]); } vector A(N); for (ll i = 0; i < N; i++) { cin >> A[i]; } // 根つき木を適当にとり,部分木のサイズを求める vector dp(N, 0); vector isvisited(N, false); vector prev(N, -1); dfs(graph, isvisited, prev, dp, 0); ll ans = 0; for (ll i = 0; i < N; i++) { ll plus = 0; ll minus = 0; ll rem = N - 1; for (ll j = 0; j < graph[i].size(); j++) { if (prev[i] != graph[i][j]) { rem -= dp[graph[i][j]]; } } for (ll j = 0; j < graph[i].size(); j++) { ll subsize = dp[graph[i][j]]; if (prev[i] == graph[i][j]) { subsize = rem; } if (A[i] < A[graph[i][j]]) { plus += subsize; } if (A[i] > A[graph[i][j]]) { minus += subsize; } } for (ll j = 0; j < graph[i].size(); j++) { ll subsize = dp[graph[i][j]]; if (prev[i] == graph[i][j]) { subsize = rem; } if (A[i] < A[graph[i][j]]) { ans += subsize * (plus - subsize); ans %= mod2; plus -= subsize; } if (A[i] > A[graph[i][j]]) { ans += subsize * (minus - subsize); ans %= mod2; minus -= subsize; } } // debug_out(i, plus, minus, ans); } cout << ans << endl; }