void solve() {
    int n, q;
    cin >> n >> q;

    vector<vector<pii>> e(n + 1, vector<pii>());
    for (int i = 1, u, v, w; i < n; i++) {
        cin >> u >> v >> w;
        e[u].push_back({v, w});
        e[v].push_back({u, w});
    }

    vector<int> dep(n + 1);
    vector<ll> len(n + 1);

    const int M = 20;
    vector<vector<int>> f(M + 1, vector<int>(n + 1));

    auto dfs = [&] (auto &&self, int u, int fa)->void {
        for (auto [v, w] : e[u]) {
            if (v == fa) continue;
            f[0][v] = u;
            dep[v] = dep[u] + 1;
            len[v] = len[u] + w;
            self(self, v, u);
        }
    };
    dfs(dfs, 1, 0);
    for (int j = 1; j <= M; j++) {
        for (int x = 1; x <= n; x++) {
            int y = f[j - 1][x];
            f[j][x] = f[j - 1][y];
        }
    }

    auto jump = [&] (int x, int len) {
        for (int j = 0; j <= M; j++) {
            if ((len >> j) & 1) {
                x = f[j][x];
            }
        }
        return x;
    };

    auto lca = [&] (int x, int y) {
        if (dep[x] < dep[y]) swap(x, y);
        x = jump(x, dep[x] - dep[y]);
        assert(dep[x] == dep[y]);
        if (x == y) return x;
        for (int j = M; j >= 0; j--) {
            int nx = f[j][x], ny = f[j][y];
            if (nx == ny) continue;
            x = nx, y = ny;
        }
        return f[0][x];
    };

    auto dis = [&] (int x, int y) {
        int l = lca(x, y);
        ll ans = len[x] - len[l] + (len[y] - len[l]);
        return ans;
    };

    while (q--) {
        int x, y;
        cin >> x >> y;
        cout << dis(x, y) << '\n';
    }
}