/**
 * @author n685
 * @brief
 * @date 2024-09-14 14:35:27
 *
 *
 */
#include "bits/stdc++.h"

#ifdef LOCAL
#include "dd/debug.h"
#else
#define dbg(...) 42
#define dbg_proj(...) 420
#define dbg_rproj(...) 420420
void nline() {}
void bar() {}
void start_clock() {}
void end_clock() {}
#endif

namespace rs = std::ranges;
namespace rv = std::views;

template <class T> constexpr T INF = T{};
template <std::floating_point T>
constexpr T INF<T> = std::numeric_limits<T>::infinity();
template <> constexpr int INF<int> = 0x3f3f3f3f; // 1061109567
template <>
constexpr int64_t INF<int64_t> = 0x3f3f3f3f3f3f3f3f; // 4557430888798830399

template <class Node>
concept SegNode = requires(Node n) {
  typename Node::Output;
  Node();
  requires std::
    same_as<std::decay_t<decltype(Node::ID)>, typename Node::Output>;
  {
    Node::comb(Node::ID, Node::ID)
  } -> std::same_as<typename Node::Output>;
  // { std::as_const(n).value() } -> std::same_as<typename Node::Output>;
  {
    n.pull(n, n)
  } -> std::same_as<void>;
};

template <SegNode Node> struct Seg {
  using Output = Node::Output;
  int sz{};
  std::vector<Node> val;
  Seg() = default;
  explicit Seg(int _sz) : sz(_sz), val(2 * sz) {}
  // explicit Seg(int _sz)
  //     : sz(static_cast<int>(std::bit_ceil<uint32_t>(_sz))),
  //       val(2 * sz) {}
  template <std::ranges::sized_range Container>
    requires requires(Container c) { Node(*std::ranges::begin(c)); }
  explicit Seg(const Container &c)
      : Seg(static_cast<int>(std::ranges::size(c))) {
    int i = sz;
    for (auto it = std::ranges::begin(c); it != std::ranges::end(c); ++it, ++i)
    {
      val[i] = Node(*it);
    }
    build(0, sz - 1);
  }

  void build(int l, int r) {
    l += sz, r += sz;
    l /= 2, r /= 2;
    for (int k = 2; l >= 1; l /= 2, r /= 2, k *= 2) {
      for (int i = l; i <= r; ++i) {
        val[i].pull(val[2 * i], val[2 * i + 1]);
      }
    }
  }

  template <class F, class... Args>
  void upd(const F &f, int i, const Args &...args) {
    std::invoke(f, val[i += sz], args...);
    for (i /= 2; i >= 1; i /= 2) {
      val[i].pull(val[2 * i], val[2 * i + 1]);
    }
  }

  template <class F, class... Args>
  Output query(const F &f, int l, int r, const Args &...args) {
    Output vl = Node::ID, vr = Node::ID;
    for (l += sz, r += sz; l <= r; l /= 2, r /= 2) {
      if (l % 2 == 1) {
        vl = Node::comb(vl, std::invoke(f, val[l++], args...));
      }
      if (r % 2 == 0) {
        vr = Node::comb(std::invoke(f, val[r--], args...), vr);
      }
    }
    return Node::comb(vl, vr);
  }

  Output query(int l, int r) { return query(&Node::value, l, r); }
};

template <class T>
  requires requires(T a) {
    {
      a + a
    } -> std::same_as<T>;
  }
struct Node {
  using Output = T;
  static constexpr Output ID{INF<T>};
  T val{ID};
  Node() = default;
  explicit Node(T v) : val(v) {}
  static Output comb(Output a, Output b) { return std::min(a, b); }
  Output value() const { return val; }
  void set(const T &v) { val = std::min(val, v); }
  void pull(const Node &cl, const Node &cr) { val = std::min(cl.val, cr.val); }
};

int main() {
#ifndef LOCAL
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
#endif

  int n;
  std::cin >> n;

  std::vector<std::vector<std::pair<int64_t, int>>> adj(n);
  for (int i = 0; i < n - 1; ++i) {
    int a, b;
    int64_t w;
    std::cin >> a >> b >> w;
    --a;
    --b;
    adj[a].emplace_back(w, b);
    adj[b].emplace_back(w, a);
  }

  std::vector<std::vector<std::pair<int64_t, int>>> iv(n);
  auto ins = [&](int a, int b, int64_t w) {
    if (a > b) {
      std::swap(a, b);
    }
    iv[a].emplace_back(w, b);
  };
  std::vector<bool> vis(n);
  std::vector<int> sub(n);
  std::vector<int64_t> dist(n);
  auto cent = [&](int node, int rt) -> int {
    int par = -1;
    while (true) {
      bool g = false;
      for (auto [w, i] : adj[node]) {
        if (i == par || vis[i]) {
          continue;
        }
        if (sub[i] * 2 > sub[rt]) {
          par = node;
          node = i;
          g = true;
          break;
        }
      }
      if (!g) {
        break;
      }
    }
    return node;
  };
  auto csub
    = [&](auto &self, int node, int par, std::vector<int> &nodes) -> void {
    nodes.push_back(node);
    sub[node] = 1;
    for (auto [w, i] : adj[node]) {
      if (i == par || vis[i]) {
        continue;
      }
      self(self, i, node, nodes);
      sub[node] += sub[i];
    }
  };
  auto comp = [&](auto &self, int node, int par) -> void {
    for (auto [w, i] : adj[node]) {
      if (i == par || vis[i]) {
        continue;
      }
      dist[i] = dist[node] + w;
      self(self, i, node);
    }
  };
  auto gen = [&](auto &self, int node) -> void {
    std::vector<int> nodes;
    csub(csub, node, -1, nodes);
    int rt = cent(node, node);
    vis[rt] = true;
    dist[rt] = 0;
    comp(comp, rt, -1);
    dbg(dist);
    rs::sort(nodes);
    std::stack<int> s;
    for (int i : nodes) {
      while (!s.empty() && dist[s.top()] > dist[i]) {
        ins(s.top(), i, dist[s.top()] + dist[i]);
        s.pop();
      }
      s.push(i);
    }
    while (!s.empty()) {
      s.pop();
    }
    for (int i : nodes | rv::reverse) {
      while (!s.empty() && dist[s.top()] > dist[i]) {
        ins(i, s.top(), dist[i] + dist[s.top()]);
        s.pop();
      }
      s.push(i);
    }
    for (auto [w, i] : adj[node]) {
      if (!vis[i]) {
        self(self, i);
      }
    }
  };
  gen(gen, 0);
  dbg(iv);

  int q;
  std::cin >> q;
  std::vector<std::vector<std::pair<int, int>>> qq(n);
  for (int i = 0; i < q; ++i) {
    int l, r;
    std::cin >> l >> r;
    --l;
    --r;
    qq[l].emplace_back(r, i);
  }

  Seg<Node<int64_t>> seg(n);
  std::vector<int64_t> ans(q);
  for (int l = n - 1; l >= 0; --l) {
    for (auto [w, r] : iv[l]) {
      seg.upd(&Node<int64_t>::set, r, w);
    }
    for (auto [r, i] : qq[l]) {
      ans[i] = seg.query(l, r);
      if (ans[i] == INF<int64_t>) {
        ans[i] = -1;
      }
    }
  }
  rs::copy(ans, std::ostream_iterator<int64_t>(std::cout, "\n"));
}