using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using static System.Console;
using Pair = System.Collections.Generic.KeyValuePair<int, int>;
//using System.Numerics;
//using static System.Math;

class Program
{
    static void Main()
    {
        SetOut(new StreamWriter(OpenStandardOutput()) { AutoFlush = false });
        new Program().solve();
        Out.Flush();
    }
    Scanner cin = new Scanner();
    readonly int[] dd = { 0, 1, 0, -1, 0 };
    readonly int mod = 1000000007;
    readonly string alfa = "abcdefghijklmnopqrstuvwxyz";
    readonly string ALFA = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    int N;
    void solve()
    {
        N = cin.nextint;
        G = Enumerable.Range(0, N).Select(i => new List<Edge>()).ToArray();
        for (int i = 0; i < N - 1; i++)
        {
            int a = cin.nextint - 1;
            int b = cin.nextint - 1;
            int c = cin.nextint;
            G[a].Add(new Edge(b, c));
            G[b].Add(new Edge(a, c));
        }
        int Q = cin.nextint;
        dijkstra(cin.nextint - 1);
        for (int i = 0; i < Q; i++)
        {
            WriteLine(D[cin.nextint - 1] + D[cin.nextint - 1]);
        }
    }

    // ref: http://abc070.contest.atcoder.jp/submissions/1505233
    struct Edge : IComparable<Edge>
    {
        public int to; public long cost;
        public Edge(int to, long cost)
        {
            this.to = to;
            this.cost = cost;
        }
        public int CompareTo(Edge e)
        {
            return cost.CompareTo(e.cost);
        }
    }
    List<Edge>[] G;
    //G = Enumerable.Range(0, N).Select(i => new List<Edge>()).ToArray();
    long[] D;
    const long inf = long.MaxValue / 3;
    void dijkstra(int s)
    {
        int n = G.Length;
        D = Enumerable.Repeat(inf, n).ToArray();
        var Q = new PriorityQueue<Edge>() { rev = true };//小さい順に取り出す
        D[s] = 0;
        Q.Enqueue(new Edge(s, D[s]));
        while (Q.Any())
        {
            //var e = Q.Dequeue();
            //var v = e.to;
            //if (D[v] < e.cost) continue;
            //foreach (var gv in G[v])
            //{
            //    if (D[gv.to] > D[v] + gv.cost)
            //    {
            //        D[gv.to] = D[v] + gv.cost;
            //        Q.Enqueue(new Edge(gv.to, D[gv.to]));
            //    }
            //}
            var p = Q.Dequeue();
            foreach (var e in G[p.to])
            {
                long d = p.cost + e.cost;
                if (D[e.to] - d > 0)
                {
                    D[e.to] = d;
                    Q.Enqueue(new Edge(e.to, d));
                }
            }
        }
    }
    class PriorityQueue<T> where T : IComparable<T>
    {
        List<T> buf;
        public bool rev = false;
        public PriorityQueue() { buf = new List<T>(); }
        int cmp(int i, int j) { return buf[i].CompareTo(buf[j]) * (rev ? -1 : 1); }
        void swap(int i, int j) { var t = buf[i]; buf[i] = buf[j]; buf[j] = t; }
        public void Enqueue(T elem)
        {
            int n = buf.Count;
            buf.Add(elem);
            while (n > 0)
            {
                int i = (n - 1) >> 1;
                if (cmp(n, i) > 0) swap(i, n);
                n = i;
            }
        }
        public T Dequeue()
        {
            T ret = buf[0];
            int n = buf.Count - 1;
            buf[0] = buf[n];
            buf.RemoveAt(n);
            for (int i = 0, j; (j = (i << 1) + 1) < n; i = j)
            {
                if (j != n - 1 && cmp(j, j + 1) < 0) ++j;
                if (cmp(i, j) < 0) swap(i, j);
            }
            return ret;
        }
        public int Count { get { return buf.Count; } }
        public bool Any() { return Count > 0; }
        public T Peek() { return buf[0]; }
    }
    
}

class Scanner
{
    string[] s; int i;
    char[] cs = new char[] { ' ' };
    public Scanner() { s = new string[0]; i = 0; }
    public string[] scan { get { return ReadLine().Split(); } }
    public int[] scanint { get { return Array.ConvertAll(scan, int.Parse); } }
    public long[] scanlong { get { return Array.ConvertAll(scan, long.Parse); } }
    public double[] scandouble { get { return Array.ConvertAll(scan, double.Parse); } }
    public string next
    {
        get
        {
            if (i < s.Length) return s[i++];
            string st = ReadLine();
            while (st == "") st = ReadLine();
            s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
            i = 0;
            return next;
        }
    }
    public int nextint { get { return int.Parse(next); } }
    public long nextlong { get { return long.Parse(next); } }
    public double nextdouble { get { return double.Parse(next); } }
}

Measured memory_bytes: 43232