#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
vector<pair<int, int> > Q[N];
vector<int> G[N];
int col[N], ans[N], sub[N], cnt[N], seg[N << 2];
bool big[N];
int n;
void upd(int pos, int val, int rt = 1, int tl = 1, int tr = n) {
  if (tl > pos || tr < pos) return;
  if (tl == tr)
    seg[rt] += val;
  else {
    int mid = (tl + tr) >> 1;
    upd(pos, val, rt << 1, tl, mid);
    upd(pos, val, rt << 1 | 1, mid + 1, tr);
    seg[rt] = seg[rt << 1] + seg[rt << 1 | 1];
  }
}
int query(int L, int R, int rt = 1, int tl = 1, int tr = n) {
  if (tl > R || tr < L) return 0;
  if (tl >= L && tr <= R) return seg[rt];
  int mid = (tl + tr) >> 1;
  return query(L, R, rt << 1, tl, mid) + query(L, R, rt << 1 | 1, mid + 1, tr);
}
void pre(int u = 1, int p = 1) {
  sub[u] = 1;
  for (int v : G[u]) {
    if (v != p) {
      pre(v, u);
      sub[u] += sub[v];
    }
  }
}
void add(int u, int p, int op) {
  if (cnt[col[u]]) upd(cnt[col[u]], -1);
  cnt[col[u]] += op;
  if (cnt[col[u]]) upd(cnt[col[u]], 1);
  for (int v : G[u]) {
    if (v != p && !big[v]) {
      add(v, u, op);
    }
  }
}
void dfs(int u = 1, int p = 1, int keep = -1) {
  int bigChild = -1, mx = 0;
  for (int v : G[u]) {
    if (v != p && sub[v] > mx) {
      mx = sub[v];
      bigChild = v;
    }
  }
  for (int v : G[u]) {
    if (v != p && v != bigChild) {
      dfs(v, u, 0);
    }
  }
  if (bigChild != -1) {
    dfs(bigChild, u, 1);
    big[bigChild] = true;
  }
  add(u, p, 1);
  for (pair<int, int> q : Q[u]) {
    ans[q.second] = query(q.first, n);
  }
  if (bigChild != -1) big[bigChild] = false;
  if (keep == 0) {
    add(u, p, -1);
  }
}
void solve() {
  int m;
  cin >> n >> m;
  for (int i = 1; i <= n; i++) {
    cin >> col[i];
  }
  for (int i = 1; i <= n - 1; i++) {
    int u, v;
    cin >> u >> v;
    G[u].push_back(v);
    G[v].push_back(u);
  }
  for (int i = 1; i <= m; i++) {
    int v, k;
    cin >> v >> k;
    Q[v].push_back({k, i});
  }
  memset(cnt, 0, sizeof(cnt));
  memset(seg, 0, sizeof(seg));
  memset(big, false, sizeof(big));
  pre();
  dfs();
  for (int i = 1; i <= m; i++) {
    cout << ans[i] << '\n';
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t = 1;
  for (int i = 1; i <= t; i++) {
    solve();
  }
  return 0;
}
