using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Text;
using static System.Console;
using static System.Convert;
using static System.Math;
using static Extentions;

class IO
{
    int idx;
    string[] input = In.ReadToEnd().Split(new[] { " ", "\n", "\r" },
        StringSplitOptions.RemoveEmptyEntries);

    T Get<T>(Func<string, T> parser) => parser(input[idx++]);

    public string S => Get(s => s);
    public char C => Get(char.Parse);
    public int I => Get(int.Parse);
    public long L => Get(long.Parse);
    public double F => Get(double.Parse);
    public decimal D => Get(decimal.Parse);
    public BigInteger B => Get(BigInteger.Parse);

    T[] Gets<T>(int n, Func<string, T> parser)
        => input.Skip((idx += n) - n).Take(n).Select(parser).ToArray();

    public string[] Ss(int n) => Gets(n, s => s);
    public char[] Cs(int n) => Gets(n, char.Parse);
    public int[] Is(int n) => Gets(n, int.Parse);
    public long[] Ls(int n) => Gets(n, long.Parse);
    public double[] Fs(int n) => Gets(n, double.Parse);
    public decimal[] Ds(int n) => Gets(n, decimal.Parse);
    public BigInteger[] Bs(int n) => Gets(n, BigInteger.Parse);

    public void Write<T>(params T[] xs) => WriteLine(string.Join(" ", xs));
    public void Write(params object[] xs) => WriteLine(string.Join(" ", xs));
}

struct Edge : IComparable<Edge>
{
    public int To, Cost;

    public Edge(int to, int cost)
    {
        To = to; Cost = cost;
    }

    public int CompareTo(Edge other) => Cost.CompareTo(other.Cost);
}

class Graph
{
    protected List<Edge>[] graph;
    protected int size;

    // [0, maxv)
    public Graph(int maxv)
    {
        graph = new List<Edge>[maxv];
        for (var i = 0; i < maxv; i++) graph[i] = new List<Edge>();
        size = maxv;
    }

    public void AddPath(int source, int target, int cost)
        => graph[source].Add(new Edge(target, cost));
}

class Dijkstra : Graph
{
    int source;
    long[] d;
    const long inf = long.MaxValue;

    public Dijkstra(int maxv) : base(maxv)
    {
        d = new long[maxv];
    }

    public void Calc(int source)
    {
        this.source = source;
        for (var i = 0; i < size; i++) d[i] = inf;
        d[source] = 0;
        var pq = new PriorityQueue<Pair<long, int>>();
        pq.Enqueue(Pair.Create(0L, source));

        while (pq.Any())
        {
            var p = pq.Dequeue();
            var v = p.Second;
            if (d[v] < p.First) continue;
            for (var i = 0; i < graph[v].Count; i++)
            {
                var e = graph[v][i];
                if (d[e.To] > d[v] + e.Cost)
                {
                    d[e.To] = d[v] + e.Cost;
                    pq.Enqueue(Pair.Create(d[e.To], e.To));
                }
            }
        }
    }

    public long GetMinCost(int source, int target)
    {
        if (source != this.source) throw new InvalidOperationException();
        return d[target];
    }
}

class PriorityQueue<T>
{
    List<T> heap;
    int size;
    Comparison<T> compare;

    public PriorityQueue()
        : this(Enumerable.Empty<T>(), Comparer<T>.Default.Compare) { }

    public PriorityQueue(IEnumerable<T> collection)
        : this(collection, Comparer<T>.Default.Compare) { }

    public PriorityQueue(Comparison<T> comparsion)
        : this(Enumerable.Empty<T>(), comparsion) { }

    public PriorityQueue(IEnumerable<T> collection, Comparison<T> comparsion)
    {
        var array = collection.ToArray();
        Array.Sort(array, comparsion);
        heap = new List<T>(array);
        size = array.Length;
        compare = comparsion;
    }

    public int Count => size;

    public bool Any() => size > 0;

    public void Clear() => size = 0;

    public void Enqueue(T item)
    {
        var i = size++;
        while (i > 0)
        {
            var p = (i - 1) >> 1;
            if (compare(heap[p], item) <= 0) break;
            if (i == heap.Count) heap.Add(heap[p]);
            else heap[i] = heap[p];
            i = p;
        }
        if (i == heap.Count) heap.Add(item);
        else heap[i] = item;
    }

    public T Dequeue()
    {
        if (size == 0) throw new InvalidOperationException();
        var r = heap[0];
        var x = heap[--size];
        var i = 0;
        while ((i << 1) + 1 < size)
        {
            var a = (i << 1) + 1;
            var b = (i << 1) + 2;
            if (b < size && compare(heap[b], heap[a]) < 0) a = b;
            if (compare(heap[a], x) >= 0) break;
            heap[i] = heap[a];
            i = a;
        }
        heap[i] = x;
        return r;
    }

    public T Peek()
    {
        if (size == 0) throw new InvalidOperationException();
        return heap[0];
    }
}

struct Pair<T1, T2> : IComparable<Pair<T1, T2>>
    where T1 : IComparable<T1>
    where T2 : IComparable<T2>
{
    public T1 First;
    public T2 Second;

    public Pair(T1 first, T2 second)
    {
        First = first;
        Second = second;
    }

    public int CompareTo(Pair<T1, T2> other)
    {
        var t = First.CompareTo(other.First);
        if (t == 0) t = Second.CompareTo(other.Second);
        return t;
    }
}

static class Pair
{
    public static Pair<T1, T2> Create<T1, T2>(T1 first, T2 second)
        where T1 : IComparable<T1>
        where T2 : IComparable<T2>
        => new Pair<T1, T2>(first, second);
}

static class Extentions
{
}

static class Program
{
    public static void Main()
    {
        var sw = new StreamWriter(OpenStandardOutput()) { NewLine = "\n" };
#if DEBUG
        sw.AutoFlush = true;
#else
        sw.AutoFlush = false;
#endif
        SetOut(sw);
        Solve(new IO());
        Out.Flush();
    }

    static void Solve(IO io)
    {
        var n = io.I;
        var dijkstra = new Dijkstra(n + 1);

        for (var i = 0; i < n - 1; i++)
        {
            var a = io.I;
            var b = io.I;
            var c = io.I;
            dijkstra.AddPath(a, b, c);
            dijkstra.AddPath(b, a, c);
        }

        var q = io.I;
        var k = io.I;
        dijkstra.Calc(k);

        for (var i = 0; i < q; i++)
        {
            var x = io.I;
            var y = io.I;
            var d = dijkstra.GetMinCost(k, x) + dijkstra.GetMinCost(k, y);
            io.Write(d);
        }
    }
}

Measured memory_bytes: 67440