#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e5 + 10;
inline int read() {
  char c = getchar();
  int x = 0, f = 1;
  while (c < '0' || c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
  return x * f;
}
int N, M, dfn[MAXN], rev[MAXN], tot, block, bel[MAXN], siz[MAXN], col[MAXN],
    tims[MAXN], Ans[MAXN], out[MAXN];
vector<int> v[MAXN];
struct Query {
  int id, l, r, k;
  bool operator<(const Query &rhs) const {
    return bel[l] == bel[rhs.l] ? r < rhs.r : bel[l] < bel[rhs.l];
  }
} Q[MAXN];
void dfs(int x, int fa) {
  dfn[x] = ++tot;
  rev[tot] = x;
  siz[x] = 1;
  for (int i = 0, to; i < v[x].size(); i++) {
    if ((to = v[x][i]) == fa) continue;
    dfs(to, x);
    siz[x] += siz[to];
  }
}
void add(int x, int opt) {
  if (opt == 1)
    Ans[++tims[x]]++;
  else
    Ans[tims[x]--]--;
}
void solve() {
  sort(Q + 1, Q + M + 1);
  int l = 1, r = 0;
  for (int i = 1; i <= M; i++) {
    while (r > Q[i].r) add(col[rev[r--]], -1);
    while (r < Q[i].r) add(col[rev[++r]], 1);
    while (l < Q[i].l) add(col[rev[l++]], -1);
    while (l > Q[i].l) add(col[rev[--l]], 1);
    out[Q[i].id] = Ans[Q[i].k];
  }
  for (int i = 1; i <= M; i++) printf("%d\n", out[i]);
}
int main() {
  N = read();
  M = read();
  block = sqrt(N);
  for (int i = 1; i <= N; i++) col[i] = read(), bel[i] = (i - 1) / block + 1;
  for (int i = 1; i <= N - 1; i++) {
    int x = read(), y = read();
    v[x].push_back(y);
    v[y].push_back(x);
  }
  dfs(1, 0);
  for (int i = 1; i <= M; i++) {
    Q[i].id = i;
    int x = read();
    Q[i].k = read();
    Q[i].l = dfn[x];
    Q[i].r = dfn[x] + siz[x] - 1;
  }
  solve();
  return 0;
}
