#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
#define fix(x) fixed << setprecision(x)
#define asc(x) x, vector<x>, greater<x>
#define rep(i, n) for(ll i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
constexpr ll INFLL = (1LL << 62), MOD = 998244353;
constexpr int INF = (1 << 30);

struct LCA{
    int _n, _log;
    vector<int> rank;
    vector<vector<int>> d;
    LCA(vector<vector<int>>& g, int root = 0){ init(g, root); }
    void init(vector<vector<int>>& g, int root = 0){
        _n = g.size(), _log = 0;
        while((1<<_log)<=_n) _log++;
        rank = vector<int>(_n);
        rank[root] = 0;
        d = vector<vector<int>>(_n, vector<int>(_log));
        dfs(-1,root,g);
        for(int j=0;j<_log-1;j++){
            for(int i=0;i<_n;i++){
                if(d[i][j]>=0) d[i][j+1] = d[d[i][j]][j];
                else d[i][j+1] = -1;
            }
        }
    }
    void dfs(int par, int now, vector<vector<int>>& g){
        d[now][0] = par;
        for(int x:g[now]){
            if(x==par) continue;
            rank[x] = rank[now]+1;
            dfs(now,x,g);
        }
    }
    int prev(int u, int x){
        assert(x>=0);
        for(int i=0;i<_log;i++){
            if(x&1) u = d[u][i];
            x >>= 1;
            if(!x) return u;
        }
        return -1;
    }
    int lca(int u, int v){
        if(rank[u]>rank[v]) swap(u,v);
        v = prev(v, rank[v]-rank[u]);
        for(int i=_log-1;i>=0;i--){
            if(d[u][i]!=d[v][i]) u = d[u][i], v = d[v][i];
        }
        if(u!=v) return d[u][0];
        return u;
    }
    int dist(int u, int v){
        return rank[u] + rank[v] - 2*lca(u,v);
    }
};

vector<int> st;
void dfs(int par, int now, vector<vector<int>>& g){
    for(int x:g[now]){
        if(x==par) continue;
        dfs(now,x,g);
        st[now] += st[x];
    }
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n,q;
    cin >> n >> q;
    vector<vector<int>> g(n);
    rep(i,n-1){
        int u,v;
        cin >> u >> v;
        u--; v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    st.assign(n,1);
    dfs(-1,0,g);
    LCA l(g);
    rep(houren,q){
        int s,t,ans;
        cin >> s >> t;
        s--; t--;
        int d = l.dist(s,t);
        if(d&1) ans = 0;
        else{
            if(l.rank[s]==l.rank[t]){
                s = l.prev(s,d/2-1);
                t = l.prev(t,d/2-1);
                ans = n - st[s] - st[t];
            }else{
                if(l.rank[s]>l.rank[t]) swap(s,t);
                s = l.prev(t,d/2-1);
                t = l.prev(t,d/2);
                ans = st[t] - st[s];
            }
        }
        cout << ans << '\n';
    }
    return 0;
}