#include <bits/stdc++.h>
 
using namespace std;
 
const int MaxN = 5e5 + 10;
const int MOD = 1e9 + 7;
const int INF = 1e9;
 
int n, m, q, a[MaxN];
vector < int > graph[MaxN];
vector < pair < int, int > > queries[MaxN];
int ans[MaxN], sz[MaxN], bs[MaxN];
int dep[MaxN], foo[MaxN], dead[MaxN];
 
void dfs(int v, int p) {
  sz[v] = 1;
  bs[v] = -1;
  for (int i = 0; i < (int)graph[v].size(); ++i) {
    int to = graph[v][i];
    if (dead[to] == 1 || to == p) {
      continue;
    }
    dfs(to, v);
    sz[v] += sz[to];
    if (bs[v] == -1 || sz[to] > sz[bs[v]]) {
      bs[v] = to;
    }
  }
}
 
void go(int v, int p, vector < pair < int, int > > &colors) {
  colors.push_back(make_pair(a[v], v));
  for (int i = 0; i < (int)graph[v].size(); ++i) {
    int to = graph[v][i];
    if (dead[to] == 1 || to == p) {
      continue;
    }
    dep[to] = dep[v] + 1;
    go(to, v, colors);
  }
}
 
void solve(int v) {
  dfs(v, -1);
  int tot = sz[v];
  while (bs[v] != -1 && sz[bs[v]] >= tot / 2) {
    v = bs[v];
  }
  dead[v] = 1;
  dep[v] = 0;
  vector < pair < int, int > > colors;
  colors.reserve(tot);
  for (int i = 0; i < (int)graph[v].size(); ++i) {
    int to = graph[v][i];
    if (dead[to] == 1) {
      continue;
    }
    dep[to] = 1;
    go(to, v, colors);
  }
  colors.push_back(make_pair(a[v], v));
  for (int i = 0; i < (int)colors.size(); ++i) {
    foo[colors[i].first] = min(foo[colors[i].first], dep[colors[i].second]);
  }
  for (int i = 0; i < (int)colors.size(); ++i) {
    int v = colors[i].second;
    for (int j = 0; j < (int)queries[v].size(); ++j) {
      int where = queries[v][j].second, color = queries[v][j].first;
//      cout << ' ' << v << ' ' << where << ' ' << color << ' ' << foo[color] << ' ' << a[v] << '\n';
      ans[where] = min(ans[where], foo[color] + dep[v]);
    }
  }
  for (int i = 0; i < (int)colors.size(); ++i) {
    foo[colors[i].first] = INF;
  }
  for (int i = 0; i < (int)graph[v].size(); ++i) {
    int to = graph[v][i];
    if (dead[to] == 1) {
      continue;
    }
    solve(to);
  }
}
 
int main() {
//  freopen("input.txt", "r", stdin);
  scanf("%d%d", &n, &m);
  srand(time(NULL));
  for (int i = 1; i <= n; ++i) {
    scanf("%d", &a[i]);
  }
  for (int i = 1; i <= m; ++i) {
    foo[i] = INF;
  }
  for (int i = 0; i < n - 1; ++i) {
    int x, y;
    scanf("%d%d", &x, &y);
    graph[x].push_back(y);
    graph[y].push_back(x);
  }
  scanf("%d", &q);
  for (int qi = 1; qi <= q; ++qi) {
    int color, v;
    scanf("%d%d", &v, &color);
    ans[qi] = INF;
    queries[v].push_back(make_pair(color, qi));
  }
  solve(1);
  for (int qi = 1; qi <= q; ++qi) {
    printf("%d\n", ans[qi]);
  }
  return 0;
}