#include <bits/stdc++.h>
using namespace std;
const int LOG = 17;
struct lowest_common_ancestor{
  vector<int> d;
  vector<vector<int>> pp;
  lowest_common_ancestor(vector<int> &p, vector<int> &d): d(d){
    int N = p.size();
    pp = vector<vector<int>>(LOG, vector<int>(N, -1));
    pp[0] = p;
    for (int i = 0; i < LOG - 1; i++){
      for (int j = 0; j < N; j++){
        if (pp[i][j] != -1){
          pp[i + 1][j] = pp[i][pp[i][j]];
        }
      }
    }
  }
  int la(int v, int x){
    for (int i = 0; i < LOG; i++){
      if ((x >> i & 1) == 1){
        v = pp[i][v];
      }
    }
    return v;
  }
  int lca(int u, int v){
    if (d[u] > d[v]){
      swap(u, v);
    }
    v = la(v, d[v] - d[u]);
    if (u == v){
      return u;
    }
    for (int i = LOG - 1; i >= 0; i--){
      if (pp[i][u] != pp[i][v]){
        u = pp[i][u];
        v = pp[i][v];
      }
    }
    return pp[0][u];
  }
};
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];
    }
  }
  lowest_common_ancestor T(p, d);
  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 if (d[A] == d[B]){
      int C = T.lca(A, B);
      if (d[A] == d[B]){
        int A2 = T.la(A, d[A] - d[C] - 1);
        int B2 = T.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 = T.la(B, D / 2);
        int Y = T.la(B, D / 2 - 1);
        cout << dp[X] - dp[Y] << endl;
      }
    }
  }
}