#include <bits/stdc++.h>
using namespace std;

#pragma GCC optimize("O3,unroll-loops")

using ll = long long;
using ii = pair<int, int>;
using iii = tuple<int, int, int>;

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define mt make_tuple

int T, n, m, sz[100005], par[100005], dep[100005], anc[25][100005], par_dist[25][100005];
bool vis[100005];
vector<int> adj[100005], all_vec[100005];
vector<ii>::iterator idx[100005];
vector<ii> chd_vec[100005];

void init(int u, int e = -1) {
	anc[0][u] = e;
	for (int k = 1; k <= 16; k++) {
		if (anc[k - 1][u] == -1) {
			break;
		}
		anc[k][u] = anc[k - 1][anc[k - 1][u]];
	}
	for (auto v : adj[u]) if (v != e) {
		dep[v] = dep[u] + 1;
		init(v, u);
	}
}

int lca(int u, int v) {
	if (dep[u] > dep[v]) {
		swap(u, v);
	}
	for (int k = 16; k >= 0; k--) {
		if (dep[v] - (1 << k) >= dep[u]) {
			v = anc[k][v];
		}
	}
	if (u == v) {
		return u;
	}
	for (int k = 16; k >= 0; k--) {
		if (anc[k][u] != anc[k][v]) {
			u = anc[k][u];
			v = anc[k][v];
		}
	}
	return anc[0][u];
}

int get_sizes(int u, int e = -1) {
	sz[u] = 1;
	for (auto v : adj[u]) if (v != e && !vis[v]) {
		sz[u] += get_sizes(v, u);
	}
	return sz[u];
}

int get_centroid(int u, int tot, int e = -1) {
	for (auto v : adj[u]) if (v != e && !vis[v] && 2 * sz[v] > tot) {
		return get_centroid(v, tot, u);
	}
	return u;
} 

void decomp(int u, int p = -1) {
	int tot = get_sizes(u);
	int c = get_centroid(u, tot);
	par[c] = p;
	vis[c] = 1;
	for (auto v : adj[c]) if (!vis[v]) {
		decomp(v, c);
	}
}

int f(int x, int k) {
	// number of nodes with distance <= k from node x
	int ret = 0;
	for (int cur = x, i = 0, prv = -1; cur != -1; prv = cur, cur = par[cur], i++) {
		int oth = k - par_dist[i][x];
		int all_con = upper_bound(all_vec[cur].begin(), all_vec[cur].end(), oth) - all_vec[cur].begin();
		int chd_con = (prv == -1 ? 0 : upper_bound(chd_vec[cur].begin(), chd_vec[cur].end(), mp(prv, oth)) - idx[prv]);
		ret += all_con - chd_con;
	}
	return ret;
}

int main() {
	memset(anc, -1, sizeof anc);
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> T;
	while (T--) {
		cin >> n >> m;
		for (int i = 1, u, v; i < n; i++) {
			cin >> u >> v;
			adj[u].pb(v);
			adj[v].pb(u);
		}
		init(1);
		decomp(1);
		for (int i = 1; i <= n; i++) {
			for (int cur = i, k = 0, prv = -1; cur != -1; prv = cur, cur = par[cur], k++) {
				int w = lca(i, cur);
				par_dist[k][i] = dep[i] + dep[cur] - 2 * dep[w];
				all_vec[cur].pb(par_dist[k][i]);
				chd_vec[cur].eb(prv, par_dist[k][i]);
			}
		}
		for (int i = 1; i <= n; i++) {
			sort(all_vec[i].begin(), all_vec[i].end());
			sort(chd_vec[i].begin(), chd_vec[i].end());
		}
		for (int i = 1; i <= n; i++) {
			if (par[i] == -1) {
				continue;
			}
			idx[i] = lower_bound(chd_vec[par[i]].begin(), chd_vec[par[i]].end(), mp(i, 0));
		}
		for (int i = 1, x, k; i <= m; i++) {
			cin >> x >> k;
			cout << f(x, k) - f(x, k - 1) << '\n';
		}
		for (int i = 1; i <= n; i++) {
			for (int k = 0; k <= 16; k++) {
				anc[k][i] = -1;
				par_dist[k][i] = 0;
			}
			dep[i] = 0;
			par[i] = 0;
			sz[i] = 0;
			vis[i] = 0;
			adj[i].clear();
			all_vec[i].clear();
			chd_vec[i].clear();
		}
	}
}