#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;
}