#include <bits/stdc++.h>
using namespace std;
#define L long long
#ifdef LOCAL
#define dbg(x) cerr << '[' << #x << " = " << (x) << "]\n";
#else
#define dbg(x)
#endif
// g++ -std=c++17 -O2 -DLOCAL -o a a.cpp

template <class T = int>
struct RMQ {
    vector<vector<int>> jmp;
    RMQ(const vector<T>& V) : jmp(1, V) {
        for (int pw = 1, k = 1; pw * 2 <= V.size(); pw *= 2, ++k) {
            jmp.emplace_back(int(V.size()) - pw * 2 + 1);
            for (int j = 0; j < jmp[k].size(); j++)
                jmp[k][j] = min(jmp[k - 1][j], jmp[k - 1][j + pw]);
        }
    }
    T query(int a, int b) {
        assert(a < b);
        int dep = 31 - __builtin_clz(b - a);
        return min(jmp[dep][a], jmp[dep][b - (1 << dep)]);
    }
};
struct LCA {
    int tim = 0;
    vector<int> time, path, ret;
    RMQ<int> rmq;
    LCA(vector<vector<int>>& g, int rt) : time(g.size()), rmq((dfs(g, rt, -1), ret)) {}
    void dfs(vector<vector<int>> &g, int u, int fa) {
        time[u] = tim++;
        for (int v : g[u]) {
            if (v == fa) continue;
            path.push_back(u), ret.push_back(time[u]);
            dfs(g, v, u);
        }
    }
    int lca(int a, int b) {
        if (a == b) return a;
        tie(a, b) = minmax(time[a], time[b]);
        return path[rmq.query(a, b)];
    }
};

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int n, q;
    cin >> n >> q;
    vector<vector<int>> edges(n);
    for (int i = 0; i < n - 1; i++) {
        int u, v;
        cin >> u >> v; u--; v--;
        edges[u].push_back(v);
        edges[v].push_back(u);
    }
    vector<int> depth(n), vis(n);
    auto dfs = [&](auto&& self, int cur, int par, int dep) {
        if (vis[cur]) return;
        vis[cur] = 1;
        depth[cur] = dep;
        for (int nbr : edges[cur]) {
            if (nbr == par) continue;
            self(self, nbr, cur, dep + 1);
        }
    };
    dfs(dfs, 0, -1, 0);
    LCA lca(edges, 0);
    auto dist = [&](int u, int v) {
        return depth[u] + depth[v] - 2 * depth[lca.lca(u, v)];
    };

    for (int i = 0; i < q; i++) {
        int l, r;
        cin >> l >> r; l--; r--;
        int d = dist(l,r)+1;
        int sol = d * d - d * (d - 1) / 2 + n - d;
        cout << sol << '\n';
    }
}

/*

5 2
1 2
2 3
2 4
4 5
1 3
4 5

*/