#include <bits/stdc++.h>
using namespace std;
int main(){
  int N, Q;
  cin >> N >> Q;
  vector<vector<int>> E(N);
  for (int i = 0; i < N - 1; i++){
    int U, V;
    cin >> U >> V;
    U--;
    V--;
    E[U].push_back(V);
    E[V].push_back(U);
  }
  vector<int> p(N, -1);
  vector<vector<int>> c(N);
  vector<int> d(N, 0);
  queue<int> q;
  q.push(0);
  vector<int> bfs;
  while (!q.empty()){
    int v = q.front();
    q.pop();
    bfs.push_back(v);
    for (int w : E[v]){
      if (w != p[v]){
        p[w] = v;
        c[v].push_back(w);
        d[w] = d[v] + 1;
        q.push(w);
      }
    }
  }
  reverse(bfs.begin(), bfs.end());
  vector<int> dp(N, 1);
  for (int v : bfs){
    for (int w : c[v]){
      dp[v] += dp[w];
    }
  }
  auto naive_lca = [&](int u, int v){
    while (d[u] > d[v]){
      u = p[u];
    }
    while (d[v] > d[u]){
      v = p[v];
    }
    while (u != v){
      u = p[u];
      v = p[v];
    }
    return u;
  };
  auto naive_la = [&](int v, int k){
    for (int i = 0; i < k; i++){
      v = p[v];
    }
    return v;
  };
  for (int i = 0; i < Q; i++){
    int A, B;
    cin >> A >> B;
    A--;
    B--;
    if (d[A] > d[B]){
      swap(A, B);
    }
    if (d[A] % 2 != d[B] % 2){
      cout << 0 << endl;
    } else {
      int C = naive_lca(A, B);
      if (d[A] == d[B]){
        int A2 = naive_la(A, d[A] - d[C] - 1);
        int B2 = naive_la(B, d[B] - d[C] - 1);
        cout << N - dp[A2] - dp[B2] << endl;
      } else {
        int D = d[A] + d[B] - d[C] * 2;
        int X = naive_la(B, D / 2);
        int Y = naive_la(B, D / 2 - 1);
        cout << dp[X] - dp[Y] << endl;
      }
    }
  }
}