#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 50;
const int B = 5;
const int mod = 998244353;
const int inv2 = (mod +	1) / 2;
const int inf = 0x3f3f3f3f;
 
inline int inc(int x, int y) { x += y - mod; return x + (x >> 31 & mod); }
inline int dec(int x, int y) { x -= y; return x + (x >> 31 & mod); }  
inline int mul(int x, int y) { return 1ll * x * y % mod; }
auto inc(const auto &first, const auto ...args) {
	return inc(first, inc(args...));
}
auto mul(const auto &first, const auto ...args) {
	return mul(first, mul(args...));
}
 
inline void upd(int &x, int y) { x = inc(x, y); }
inline void dpu(int &x, int y) { x = dec(x, y); }
inline void pud(int &x, int y) { x = mul(x, y); }
 

int n, X, a[N], fa[N], dp[N][3];
bool ban[N][1 << B][2];
vector<int> G[N], sons[N];

void dfs(int x, int f) {
	fa[x] = f;
	for (int y : G[x]) if (y != f) {
		sons[x].push_back(y);
		dfs(y, x);
	}
	for (int mask = 0; mask < (1 << sons[x].size()); ++mask) {
		for (int o_fa : {0, 1}) {
			int sum = 0, cnt = 0;
			for (int i = 0; i < sons[x].size(); ++i)
				if (mask >> i & 1) {
					sum += a[sons[x][i]];
					++cnt;
				}
			if (o_fa) {
				sum += a[fa[x]];
				++cnt;
			}
			sum += a[x];
			++cnt;
			if (cnt > 1 && sum > X * cnt) {
				ban[x][mask][o_fa] = true;
			}
		}
	}
}

void solve(int x) {
	for (int y : sons[x]) {
		solve(y);
	}
	// father is chosen
	// 0: x is chosen, fa[x] is NOT chosen
	// 1: x is chosen, fa[x] is chosen
	// 2: x is not chosen
	for (int o : {0, 1}) {
		if (x == 1 && o == 1) continue;
		for (int mask = 0; mask < (1 << sons[x].size()); ++mask) {
			if (ban[x][mask][o])
				continue;
			int ways = 1;
			for (int i = 0; i < sons[x].size(); ++i)
				if (mask >> i & 1) {
					pud(ways, dp[sons[x][i]][1]);
				}
				else {
					pud(ways, dp[sons[x][i]][2]);
				}
			upd(dp[x][o], ways);
		}
	}
	int ways = 1;
	for (int y : sons[x]) {
		pud(ways, inc(dp[y][0], dp[y][2]));
	}
	dp[x][2] = ways;
}	

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	int T;
	cin >> T;
	while (T--) {
		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);
		}
		dfs(1, 0);
	
		solve(1);
		cout << inc(dp[1][0], dp[1][2]) << '\n';
		memset(ban, 0, sizeof ban);
		memset(dp, 0, sizeof dp);
		for (int i = 1; i <= n; ++i) {
			G[i].clear();
			sons[i].clear();
		}
	}
}