#include <bits/stdc++.h>
#include <boost/range/algorithm.hpp>
#include <boost/range/numeric.hpp>
#include <boost/integer/common_factor.hpp>
#include <boost/integer/common_factor_rt.hpp>
#include <boost/multiprecision/cpp_dec_float.hpp>
#include <boost/multiprecision/cpp_int.hpp>

using std::string;
using std::vector;
using std::set;
using std::multiset;
using std::unordered_set;
using std::map;
using std::multimap;
using std::unordered_map;
using std::pair;
using std::cin;
using std::cout;

using boost::multiprecision::cpp_int;
using cpp_dec_float_1000 = boost::multiprecision::number<boost::multiprecision::cpp_dec_float<1000, boost::int128_type>>;

typedef uintmax_t    ull;
typedef intmax_t     ll;
typedef uint64_t     ul;
typedef uint32_t     ui;
typedef uint8_t      uc;

constexpr char CRLF  = '\n';
constexpr char SPACE = ' ';
constexpr char VECTOR_COUT_SEPARATOR = SPACE;
constexpr ll INF = 1000'000'007;
constexpr int MOD = 1000'000'007;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> std::ostream& operator<< (std::ostream& os, const std::vector<T>& vc) { for(auto it = vc.begin(); it != vc.end(); ++it) { if (std::next(it) == vc.end()) os << *it; else os << *it << VECTOR_COUT_SEPARATOR; } return os; }
template<class T1, class T2> inline std::ostream & operator<< (std::ostream & os, const std::pair<T1, T2> & p) { return os << p.first << ' ' << p.second; }
template<class T> T modinv(T a, T m) { T b = m, u = 1, v = 0; while (b) { T t = a / b; a -= t * b; boost::swap(a, b); u -= t * v; boost::swap(u, v); } u %= m; if (u < 0) u += m; return u; }
template<class T> inline bool isSosuu(const T& n) { if (n == T(1)) { return false; } for (T i = 2; i*i <= n; ++i) { if (n % i == 0) { return false; } } return true; }
template<class T> vector<vector<T>> split (const vector<T>& S, T delim) { vector<vector<T>> ret{}; vector<T> buff{}; for (auto c : S) { if (c == delim) { if (!buff.empty()) ret.push_back(buff); buff.clear(); } else { buff.push_back(c); } } if (!buff.empty()) ret.push_back(buff); return ret; }

struct Tmp
{
public:
  int N, K;
  vector<vector<pair<int, int>>> tree;
  // vector<int> memo;
  vector<ll> distance;
  Tmp(int N)
  : N(N)
  , K()
  , tree(N)
  // , memo(N)
  , distance(N)
  {}

  void pre(int k) {
    K = k;
    rec(k, -1, 0);
  }

  void rec(int cur, int par, ll dis) {
    distance[cur] = dis;
    for (const auto& p : tree[cur]) {
      if (p.first != par) {
        rec(p.first, cur, dis + p.second);
      }
    }
  }

  ll operator() (int x, int y) {
    return distance[x] + distance[y];
  }
};

void solve(void)
{
  int N; cin >> N;
  Tmp t(N);
  for (int i = 0; i < N-1; ++i) {
    int a, b, c; cin >> a >> b >> c;
    --a; --b;
    t.tree[a].push_back({b, c});
    t.tree[b].push_back({a, c});
  }
  int Q, K; cin >> Q >> K;
  --K;
  t.pre(K);
  for (int _ = 0; _ < Q; ++_) {
    int x, y; cin >> x >> y;
    --x; --y;
    cout << t(x, y) << CRLF;
  }
  return;
}

int main(void)
{
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(0);

  solve();

  return 0;
}


Measured memory_bytes: 11264