#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

template<typename T>
vector<vector<T>> vec2d(int n, int m, T v){
    return vector<vector<T>>(n, vector<T>(m, v));
}

template<typename T>
vector<vector<vector<T>>> vec3d(int n, int m, int k, T v){
    return vector<vector<vector<T>>>(n, vector<vector<T>>(m, vector<T>(k, v)));
}

template<typename T>
void print_vector(vector<T> v, char delimiter=' '){
    if(v.empty()) {
        cout << endl;
        return;
    }
    for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter;
    cout << v.back() << endl;
}

class Lca{
    public:
        vector<int> depth;
        vector<vector<int>> parent;
        vector<int> subtree_size;
        vector<vector<int>> G;
        int root;
        int n;
        const int N_LOG_MAX = 20;
        bool initialized = false;

        Lca(vector<vector<int>> g, int _root){
            n = g.size();
            G = g;
            root = _root;
            subtree_size = vector<int>(n, 0);
            parent = vector<vector<int>>(N_LOG_MAX, vector<int>(n));
            depth = vector<int>(n, 0);
        }

        void init(){
            initialized = true;
            dfs(root, -1, 0);
            for(int i = 0; i < N_LOG_MAX-1; i++){
                for(int v = 0; v < n; v++){
                    if(parent[i][v] < 0) parent[i+1][v] = -1;
                    else parent[i+1][v] = parent[i][parent[i][v]];
                }
            }
        }

        int lca(int u, int v){
            assert(initialized);
            if(depth[u] > depth[v]) swap(u, v);
            for(int i = 0; i < N_LOG_MAX; i++){
                if((depth[v] - depth[u]) >> i & 1){
                    v = parent[i][v];
                }
            }
            if(u == v) return u;
            for(int i = N_LOG_MAX-1; i >= 0; i--){
                if(parent[i][u] != parent[i][v]) {
                    u = parent[i][u];
                    v = parent[i][v];
                }
            }
            return parent[0][u];
        }

        int dist(int u, int v){
            int l = lca(u, v);
            return depth[u]+depth[v]-2*depth[l];
        }

        int go_parent(int v, int cnt){
            int cur = v;
            for(int i = 0; i < N_LOG_MAX; i++){
                if(cnt&(1<<i)) cur = parent[i][cur];
            }
            return cur;
        }

    private:
        void dfs(int v, int p, int d){
            subtree_size[v] = 1;
            parent[0][v] = p;
            depth[v] = d;
            for(int i = 0; i < G[v].size(); i++){
                if(G[v][i] != p) {
                    dfs(G[v][i], v, d+1); 
                    subtree_size[v] += subtree_size[G[v][i]];
                }
            }
        }
};


int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    int n, q; cin >> n >> q;
    vector<vector<int>> g(n);
    for(int i = 0; i < n-1; i++){
        int a, b; cin >> a >> b; a--; b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    auto lca = Lca(g, 0);
    lca.init();
    while(q--){
        int s, t; cin >> s >> t; s--; t--;
        if(lca.depth[s] > lca.depth[t]) swap(s, t);
        auto l = lca.lca(s, t);
        if(lca.depth[s] == lca.depth[t]){
            int d = lca.depth[s]-lca.depth[l];
            int ss = lca.go_parent(s, d-1);
            int tt = lca.go_parent(t, d-1);
            int ans = n-lca.subtree_size[ss]-lca.subtree_size[tt];
            cout << ans << endl;
        }else{
            int dist_st = lca.dist(s, t);
            if(dist_st%2 == 1){
                cout << 0 << endl;
                continue;
            }
            int d = dist_st/2;
            int c = lca.go_parent(t, d);
            int c_ch = lca.go_parent(t, d-1);
            int ans = lca.subtree_size[c]-lca.subtree_size[c_ch];
            cout << ans << endl;
        }
    }
}