#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define per(i, n) for (int i = (n)-1; i >= 0; i--)
#define rep2(i, l, r) for (int i = (l); i < (r); i++)
#define per2(i, l, r) for (int i = (r)-1; i >= (l); i--)
#define each(e, v) for (auto &e : v)
#define MM << " " <<
#define pb push_back
#define eb emplace_back
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define sz(x) (int)x.size()
using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;

template <typename T>
using minheap = priority_queue<T, vector<T>, greater<T>>;

template <typename T>
using maxheap = priority_queue<T>;

template <typename T>
bool chmax(T &x, const T &y) {
    return (x < y) ? (x = y, true) : false;
}

template <typename T>
bool chmin(T &x, const T &y) {
    return (x > y) ? (x = y, true) : false;
}

template <typename T>
int flg(T x, int i) {
    return (x >> i) & 1;
}

int pct(int x) { return __builtin_popcount(x); }
int pct(ll x) { return __builtin_popcountll(x); }
int topbit(int x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(ll x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
int botbit(int x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int botbit(ll x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }

template <typename T>
void print(const vector<T> &v, T x = 0) {
    int n = v.size();
    for (int i = 0; i < n; i++) cout << v[i] + x << (i == n - 1 ? '\n' : ' ');
    if (v.empty()) cout << '\n';
}

template <typename T>
void printn(const vector<T> &v, T x = 0) {
    int n = v.size();
    for (int i = 0; i < n; i++) cout << v[i] + x << '\n';
}

template <typename T>
int lb(const vector<T> &v, T x) {
    return lower_bound(begin(v), end(v), x) - begin(v);
}

template <typename T>
int ub(const vector<T> &v, T x) {
    return upper_bound(begin(v), end(v), x) - begin(v);
}

template <typename T>
void rearrange(vector<T> &v) {
    sort(begin(v), end(v));
    v.erase(unique(begin(v), end(v)), end(v));
}

template <typename T>
vector<int> id_sort(const vector<T> &v, bool greater = false) {
    int n = v.size();
    vector<int> ret(n);
    iota(begin(ret), end(ret), 0);
    sort(begin(ret), end(ret), [&](int i, int j) { return greater ? v[i] > v[j] : v[i] < v[j]; });
    return ret;
}

template <typename T>
void reorder(vector<T> &a, const vector<int> &ord) {
    int n = a.size();
    vector<T> b(n);
    for (int i = 0; i < n; i++) b[i] = a[ord[i]];
    swap(a, b);
}

template <typename T>
T floor(T x, T y) {
    assert(y != 0);
    if (y < 0) x = -x, y = -y;
    return (x >= 0 ? x / y : (x - y + 1) / y);
}

template <typename T>
T ceil(T x, T y) {
    assert(y != 0);
    if (y < 0) x = -x, y = -y;
    return (x >= 0 ? (x + y - 1) / y : x / y);
}

template <typename S, typename T>
pair<S, T> operator+(const pair<S, T> &p, const pair<S, T> &q) {
    return make_pair(p.first + q.first, p.second + q.second);
}

template <typename S, typename T>
pair<S, T> operator-(const pair<S, T> &p, const pair<S, T> &q) {
    return make_pair(p.first - q.first, p.second - q.second);
}

template <typename S, typename T>
istream &operator>>(istream &is, pair<S, T> &p) {
    S a;
    T b;
    is >> a >> b;
    p = make_pair(a, b);
    return is;
}

template <typename S, typename T>
ostream &operator<<(ostream &os, const pair<S, T> &p) {
    return os << p.first << ' ' << p.second;
}

struct io_setup {
    io_setup() {
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        cout << fixed << setprecision(15);
    }
} io_setup;

constexpr int inf = (1 << 30) - 1;
constexpr ll INF = (1LL << 60) - 1;
// constexpr int MOD = 1000000007;
constexpr int MOD = 998244353;

template <bool directed = false>
struct Heavy_Light_Decomposition {
    struct edge {
        int to, id;
        edge(int to, int id) : to(to), id(id) {}
    };

    vector<vector<edge>> es;
    vector<int> par, si, depth;
    vector<int> root;       // 属する連結成分の根
    vector<int> id_v, id_e; // 各頂点、各辺が一列に並べたときに何番目に相当するか (辺の番号は 1,2,...,n-1 となることに注意)
    vector<int> vs;
    const int n;
    int m;

    Heavy_Light_Decomposition(int n) : es(n), par(n), si(n, 1), depth(n, -1), root(n), id_v(n), id_e(n - 1), vs(n), n(n), m(0) {}

    void add_edge(int from, int to) {
        es[from].emplace_back(to, m);
        if (!directed) es[to].emplace_back(from, m);
        m++;
    }

    int bfs_sz(int r, int s) {
        int t = s;
        queue<int> que;
        que.push(r);
        depth[r] = 0;
        vs[t++] = r;
        while (!que.empty()) {
            int i = que.front();
            que.pop();
            for (auto &e : es[i]) {
                if (depth[e.to] != -1) continue;
                par[e.to] = i;
                depth[e.to] = depth[i] + 1;
                vs[t++] = e.to;
                que.push(e.to);
            }
        }
        for (int i = t - 1; i >= s; i--) {
            for (auto &e : es[vs[i]]) {
                if (e.to != par[vs[i]]) si[vs[i]] += si[e.to];
            }
        }
        return t;
    }

    void bfs_hld(int r, int s) {
        id_v[r] = s;
        root[r] = r;
        queue<int> que;
        que.push(r);
        while (!que.empty()) {
            int i = que.front();
            que.pop();
            edge heavy = {-1, -1};
            int ma = 0;
            for (auto &e : es[i]) {
                if (e.to == par[i]) continue;
                if (ma < si[e.to]) ma = si[e.to], heavy = e;
            }
            int cnt = id_v[i] + 1;
            if (heavy.id != -1) {
                root[heavy.to] = root[i];
                id_e[heavy.id] = cnt;
                id_v[heavy.to] = cnt;
                que.push(heavy.to);
                cnt += si[heavy.to];
            }
            for (auto &e : es[i]) {
                if (e.to == par[i] || e.id == heavy.id) continue;
                root[e.to] = e.to;
                id_e[e.id] = cnt;
                id_v[e.to] = cnt;
                que.push(e.to);
                cnt += si[e.to];
            }
        }
    }

    void decompose() {
        int s = 0;
        for (int i = 0; i < n; i++) {
            if (depth[i] != -1) continue;
            int t = bfs_sz(i, s);
            bfs_hld(i, s);
            s = t;
        }
        for (int i = 0; i < n; i++) vs[id_v[i]] = i;
    }

    int lca(int u, int v) {
        while (root[u] != root[v]) {
            if (depth[root[u]] > depth[root[v]]) swap(u, v);
            v = par[root[v]];
        }
        if (depth[u] > depth[v]) swap(u, v);
        return u;
    }

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

    // u の k 個前の祖先
    int ancestor(int u, int k) {
        if (k > depth[u]) return -1;
        while (k > 0) {
            int r = root[u];
            int l = depth[u] - depth[r];
            if (k <= l) return vs[id_v[r] + l - k];
            u = par[r];
            k -= l + 1;
        }
        return u;
    }

    // u から v の方向へ k 回移動
    int move(int u, int v, int k) {
        int w = lca(u, v);
        int l = depth[u] + depth[v] - depth[w] * 2;
        if (k > l) return -1;
        if (k <= depth[u] - depth[w]) return ancestor(u, k);
        return ancestor(v, l - k);
    }

    // パスに対応する区間たちを列挙
    vector<pair<int, int>> get_path(int u, int v, bool use_edge = false) {
        vector<pair<int, int>> ret;
        while (root[u] != root[v]) {
            if (depth[root[u]] > depth[root[v]]) swap(u, v);
            ret.emplace_back(id_v[root[v]], id_v[v] + 1);
            v = par[root[v]];
        }
        if (depth[u] > depth[v]) swap(u, v);
        ret.emplace_back(id_v[u] + use_edge, id_v[v] + 1);
        return ret;
    }

    // クエリが非可換の場合 (l > r なら子から親方向で [r,l)、l < r なら親から子方向で [l,r))
    vector<pair<int, int>> get_path_noncommutative(int u, int v, bool use_edge = false) {
        vector<pair<int, int>> l, r;
        while (root[u] != root[v]) {
            if (depth[root[u]] > depth[root[v]]) {
                l.emplace_back(id_v[u] + 1, id_v[root[u]]);
                u = par[root[u]];
            } else {
                r.emplace_back(id_v[root[v]], id_v[v] + 1);
                v = par[root[v]];
            }
        }
        if (depth[u] > depth[v]) {
            l.emplace_back(id_v[u] + 1, id_v[v] + use_edge);
        } else {
            r.emplace_back(id_v[u] + use_edge, id_v[v] + 1);
        }
        reverse(begin(r), end(r));
        for (auto &e : r) l.push_back(e);
        return l;
    }
};

void solve() {
    int N, Q;
    cin >> N >> Q;

    Heavy_Light_Decomposition G(N);

    rep(i, N - 1) {
        int u, v;
        cin >> u >> v;
        u--, v--;
        G.add_edge(u, v);
    }
    G.decompose();

    while (Q--) {
        int u, v;
        cin >> u >> v;
        u--, v--;

        int d = G.dist(u, v);
        if (d % 2 == 1) {
            cout << "0\n";
            continue;
        }

        d /= 2;
        if (G.depth[u] < G.depth[v]) swap(u, v);

        if (G.depth[u] > G.depth[v]) {
            int w1 = G.ancestor(u, d), w2 = G.ancestor(u, d - 1);
            cout << G.si[w1] - G.si[w2] << '\n';
        } else {
            int w1 = G.ancestor(u, d), w2 = G.ancestor(u, d - 1), w3 = G.ancestor(v, d - 1);
            cout << N - G.si[w2] - G.si[w3] << '\n';
        }
    }
}

int main() {
    int T = 1;
    // cin >> T;
    while (T--) solve();
}