#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>> 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...); } using mint = modint998244353; void debug_mint1(vector &vec) { for (int i = 0; i < vec.size(); i++) { cerr << vec[i].val() << " "; } cerr << endl; } void debug_mint2(vector> &vec) { for (int i = 0; i < vec.size(); i++) { for (int j = 0; j < vec[i].size(); j++) { cerr << vec[i][j].val() << " "; } cerr << endl; } } vector A; mint merge(mint a, mint b){ return a + b; } mint e(){ return mint(0); } mint put_edge(mint x, int i){ return x; } mint put_vertex(mint x, int v){ return x * mint(A[v]) + mint(A[v]); } // 全方位木 DP の抽象化ライブラリ // https://trap.jp/post/1702/ template struct RerootingDP { struct edge { int to, idx, xdi; }; RerootingDP(int n_ = 0) : n(n_), inner_edge_id(0) { es.resize(2 * n - 2); start.resize(2 * n - 2); if (n == 1) es_build(); } void add_edge(int u, int v, int idx, int xdi) { start[inner_edge_id] = u; es[inner_edge_id] = {v, idx, xdi}; inner_edge_id++; start[inner_edge_id] = v; es[inner_edge_id] = {u, xdi, idx}; inner_edge_id++; if (inner_edge_id == 2 * n - 2) { es_build(); } } vector build(int root_ = 0) { root = root_; vector subdp(n); subdp[0] = put_vertex(e(), 0); outs.resize(n); vector geta(n + 1, 0); for (int i = 0; i < n; i++) geta[i + 1] = start[i + 1] - start[i] - 1; geta[root + 1]++; for (int i = 0; i < n; i++) geta[i + 1] += geta[i]; auto dfs = [&](auto sfs, int v, int f) -> void { E val = e(); for (int i = start[v]; i < start[v + 1]; i++) { if (es[i].to == f) { swap(es[start[v + 1] - 1], es[i]); } if (es[i].to == f) continue; sfs(sfs, es[i].to, v); E nval = put_edge(subdp[es[i].to], es[i].idx); outs[geta[v]++] = nval; val = merge(val, nval); } subdp[v] = put_vertex(val, v); }; dfs(dfs, root, -1); return subdp; } vector reroot() { vector reverse_edge(n); reverse_edge[root] = e(); vector answers(n); auto dfs = [&](auto sfs, int v) -> void { int le = outs_start(v); int ri = outs_start(v + 1); int siz = ri - le; vector rui(siz + 1); rui[siz] = e(); for (int i = siz - 1; i >= 0; i--) { rui[i] = merge(outs[le + i], rui[i + 1]); } answers[v] = put_vertex(merge(rui[0], reverse_edge[v]), v); E lui = e(); for (int i = 0; i < siz; i++) { V rdp = put_vertex( merge(merge(lui, rui[i + 1]), reverse_edge[v]), v); reverse_edge[es[start[v] + i].to] = put_edge(rdp, es[start[v] + i].xdi); lui = merge(lui, outs[le + i]); sfs(sfs, es[start[v] + i].to); } }; dfs(dfs, root); return answers; } private: int n, root, inner_edge_id; vector outs; vector es; vector start; int outs_start(int v) { int res = start[v] - v; if (root < v) res++; return res; } void es_build() { vector nes(2 * n - 2); vector nstart(n + 2, 0); for (int i = 0; i < 2 * n - 2; i++) nstart[start[i] + 2]++; for (int i = 0; i < n; i++) nstart[i + 1] += nstart[i]; for (int i = 0; i < 2 * n - 2; i++) nes[nstart[start[i] + 1]++] = es[i]; swap(es, nes); swap(start, nstart); } }; int main() { ll N; cin >> N; A.resize(N); rep(i, N){ cin >> A[i]; } vector U(N - 1); vector V(N - 1); rep(i, N - 1){ cin >> U[i] >> V[i]; U[i]--; V[i]--; } RerootingDP treedp(N); for (ll i = 0; i < N - 1; i++){ treedp.add_edge(U[i], V[i], i, i); } treedp.build(); vector ans = treedp.reroot(); mint all_ans = mint(0); for (ll i = 0; i < N; i++){ all_ans += ans[i]; } // debug_mint1(ans); for (ll i = 0; i < N; i++){ all_ans -= mint(A[i]); } cout << (all_ans / mint(2)).val() << endl; }