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#include <iostream>
#include <vector>
const int N = 100010;
struct Node {
int w;
std::vector<int> children;
};
int n;
Node nodes[N];
bool visited[N];
long long contain_root[N];
long long contain_or_not_contain_root[N];
void dfs(int i) {
visited[i] = true;
long long this_contain_root = nodes[i].w;
long long this_contain_or_not_contain_root = nodes[i].w;
for (auto next : nodes[i].children) {
if (!visited[next]) {
dfs(next);
if (contain_root[next] > 0) {
this_contain_root += contain_root[next];
}
if (contain_or_not_contain_root[next] >
this_contain_or_not_contain_root) {
this_contain_or_not_contain_root = contain_or_not_contain_root[next];
}
}
}
if (this_contain_root > this_contain_or_not_contain_root) {
this_contain_or_not_contain_root = this_contain_root;
}
contain_root[i] = this_contain_root;
contain_or_not_contain_root[i] = this_contain_or_not_contain_root;
}
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
std::cin >> n;
for (int i = 1; i <= n; i++) {
std::cin >> nodes[i].w;
}
for (int i = 1; i < n; i++) {
int a, b;
std::cin >> a >> b;
nodes[a].children.push_back(b);
nodes[b].children.push_back(a);
}
dfs(1);
std::cout << contain_or_not_contain_root[1];
return 0;
}
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