#include <bits/stdc++.h>

#define LL long long
#define ull unsigned long long
#define F(i, j, k) for (int i = j; i <= k; ++i)
#define DF(i, j, k) for (int i = j; i >= k; --i)

using namespace std;

template <typename T> inline void read(T &n) {
    T w = 1;
    n = 0;
    char ch = getchar();
    while (!isdigit(ch) && ch != EOF) {
        if (ch == '-') w = -1;
        ch = getchar();
    }
    while (isdigit(ch) && ch != EOF) {
        n = (n << 3) + (n << 1) + (ch & 15);
        ch = getchar();
    }
    n *= w;
}

template <typename T> inline void write(T x) {
    T l = 0;
    ull y = 0;
    if (!x) { putchar(48); return; }
    if (x < 0) { x = -x; putchar('-'); }
    while (x) { y = y * 10 + x % 10; x /= 10; ++l; }
    while (l) { putchar(y % 10 + 48); y /= 10; --l; }
}

template <typename T> inline void writes(T x) {
    write(x);
    putchar(' ');
}

template <typename T> inline void writeln(T x) {
    write(x);
    puts("");
}

template <typename T> inline void checkmax(T &a, T b) { a = a > b ? a : b; }

template <typename T> inline void checkmin(T &a, T b) { a = a < b ? a : b; }

const int N = 1e6 + 100;

int a[N];

int n, k, cnt, ans, head[N], nxt[N << 1], to[N << 1], dp[N][2];

inline void addedge(int x, int y) {
    nxt[++cnt] = head[x];
    to[cnt] = y;
    head[x] = cnt;
}

inline void dfs(int x, int fa) {
    int sum = 0, mx = 0;
    for (int i = head[x]; i; i = nxt[i]) {
        if (to[i] == fa) continue;
        dfs(to[i], x);
        sum += max(dp[to[i]][0], dp[to[i]][1]);
        if (dp[to[i]][1] == 0) continue;
        if (!mx) mx = abs(dp[to[i]][0] - dp[to[i]][1]);
        else mx = min(mx, abs(dp[to[i]][0] - dp[to[i]][1]));
    }
    sum += a[x];
    dp[x][sum & 1] = sum;
    if (!mx) dp[x][!(sum & 1)] = 0;
    else dp[x][(sum - mx) & 1] = sum - mx;
    if (dp[x][k & 1] >= k) {
        ++ans;
        dp[x][0] = dp[x][1] = 0;
    }
}

inline void solve() {
    read(n); read(k);
    cnt = ans = 0;
    F(i, 1, n) head[i] = dp[i][0] = dp[i][1] = 0;
    F(i, 1, n) read(a[i]);
    F(i, 1, n - 1) {
        int x, y;
        read(x); read(y);
        addedge(x, y);
        addedge(y, x);
    }
    dfs(1, 0);
    cout << ans << '\n';
}

int main() {
    //freopen(".in", "r", stdin);
    //freopen(".out", "w", stdout);
    int t; read(t);
    while (t--) solve();
    return 0;
}