#include <bits/stdc++.h>
using namespace std;
#define all(x) begin(x), end(x)
#define int int64_t
const int maxn = 1e5 + 42;
vector<int> g[maxn];
int x;
int A[maxn];
void init() {
for(int i = 0; i < maxn; i++) {
g[i].clear();
}
}
int dfs(int v = 1, int p = 1) {
int res = 0;
for(auto u: g[v]) {
if(u != p) {
res += dfs(u, v);
}
}
return max(A[v] + res, -x);
}
void solve() {
init();
int n;
cin >> n >> x;
for(int i = 1; i <= n; i++) {
cin >> A[i];
}
for(int i = 1; i < n; i++) {
int x, y;
cin >> x >> y;
g[x].push_back(y);
g[y].push_back(x);
}
cout << dfs() << endl;
}
signed main() {
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
ios::sync_with_stdio(0);
cin.tie(0);
int t;
cin >> t;
while(t--) {
solve();
}
return 0;
}
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