#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using mint = modint998244353;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vmi = vector<mint>;
using vvmi = vector<vmi>;
using vvvmi = vector<vvmi>;
#define all(a) (a).begin(), (a).end()
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)

struct RootedTreeLCA {
  int n;
  int LOG;
  vector<vector<int>> g;
  vector<int> depth;
  vector<int> par;
  vector<vector<int>> ch;
  vector<vector<int>> up;

  // NEW: Euler tour times
  vector<int> tin, tout;
  int timer;

  RootedTreeLCA(int n = 0) { init(n); }

  void init(int n_) {
    n = n_;
    g.assign(n, {});
    depth.assign(n, 0);
    par.assign(n, -1);
    ch.assign(n, {});
    tin.assign(n, 0);
    tout.assign(n, 0);
    timer = 0;

    LOG = 1;
    while ((1 << LOG) <= max(1, n)) LOG++;
    up.assign(LOG, vector<int>(n, -1));
  }

  void add_edge(int u, int v) {
    g[u].push_back(v);
    g[v].push_back(u);
  }

  void build(int root = 0) {
    fill(par.begin(), par.end(), -1);
    fill(depth.begin(), depth.end(), 0);
    for (auto &v : ch) v.clear();
    for (auto &row : up) fill(row.begin(), row.end(), -1);
    timer = 0;

    vector<int> st;
    vector<int> it(n, 0);
    st.reserve(n);
    st.push_back(root);
    par[root] = -1;
    depth[root] = 0;

    while (!st.empty()) {
      int v = st.back();

      // first visit
      if (it[v] == 0) {
        tin[v] = timer++;
      }

      if (it[v] == (int)g[v].size()) {
        tout[v] = timer;
        st.pop_back();
        continue;
      }

      int to = g[v][it[v]++];
      if (to == par[v]) continue;

      par[to] = v;
      depth[to] = depth[v] + 1;
      ch[v].push_back(to);
      st.push_back(to);
    }

    for (int v = 0; v < n; v++) up[0][v] = par[v];
    for (int j = 1; j < LOG; j++) {
      for (int v = 0; v < n; v++) {
        int p = up[j - 1][v];
        up[j][v] = (p == -1 ? -1 : up[j - 1][p]);
      }
    }
  }

  // ===== 基本 API =====
  int parent(int v) const { return par[v]; }
  const vector<int>& children(int v) const { return ch[v]; }
  int get_depth(int v) const { return depth[v]; }

  // ===== LCA =====
  int kth_ancestor(int v, long long k) const {
    for (int j = 0; j < LOG; j++) {
      if (v == -1) return -1;
      if (k & (1LL << j)) v = up[j][v];
    }
    return v;
  }

  int lca(int a, int b) const {
    if (depth[a] < depth[b]) swap(a, b);
    a = kth_ancestor(a, depth[a] - depth[b]);
    if (a == b) return a;
    for (int j = LOG - 1; j >= 0; j--) {
      if (up[j][a] != up[j][b]) {
        a = up[j][a];
        b = up[j][b];
      }
    }
    return up[0][a];
  }

  int dist(int a, int b) const {
    int c = lca(a, b);
    return depth[a] + depth[b] - 2 * depth[c];
  }

  // start:v, goal:u
  int jump_on_path(int v, int u, int t) const {
    int c = lca(v, u);
    int dv = depth[v] - depth[c];
    int du = depth[u] - depth[c];
    int d = dv + du;
    if (t < 0 || t > d) return -1;
    if (t <= dv) return kth_ancestor(v, t);
    return kth_ancestor(u, d - t);
  }

  int center_node_if_even_dist(int u, int v) const {
    int d = dist(u, v);
    if (d & 1) return -1;
    return jump_on_path(u, v, d / 2);
  }

  // ===== NEW: subtree check =====
  // is u in subtree of v?
  bool is_in_subtree(int u, int v) const {
    return tin[v] <= tin[u] && tin[u] < tout[v];
  }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, q; cin >> n >> q;
    RootedTreeLCA tr(n);
    rep(i, n-1){
        int u, v; cin >> u >> v;
        u--; v--;
        tr.add_edge(u, v);
    }tr.build(0);

    vi nodes(n, 1), tmp(n, 0);
    queue<int> que;
    rep(i, n){
        tmp[i] = tr.children(i).size();
        if(tmp[i] == 0){
            que.push(i);
        }
    }
    while(!que.empty()){
        auto u = que.front(); que.pop();
        int pa = tr.parent(u);
        nodes[pa] += nodes[u];
        tmp[pa]--;
        if(pa == 0)continue;
        if(tmp[pa] == 0)que.push(pa);
    }
    
    while(q--){
        int s, t; cin >> s >> t;
        s--; t--;
        int d = tr.dist(s, t);
        if(d % 2 != 0){
            cout << 0 << endl;
            continue;
        }
        int x = tr.jump_on_path(s, t, d/2);
        int ans = nodes[x];
        if(tr.is_in_subtree(s, x)){
            int d2 = tr.dist(s, x);
            int y = tr.jump_on_path(s, x, d2-1);
            ans -= nodes[y];
        }
        if(tr.is_in_subtree(t, x)){
            int d2 = tr.dist(t, x);
            int y = tr.jump_on_path(t, x, d2-1);
            ans -= nodes[y];
        }
        cout << ans << endl;
    }

    return 0;
}