using System;
using System.Collections.Generic;
using System.Text;

public class Program
{
    private int N;
    private List<E>[] Edges;
    private int Q, K;

    private long[] Cost;

    public void Solve()
    {
        var sc = new Scanner();
        N = sc.NextInt();
        Edges = new List<E>[N];
        for (int i = 0; i < N; i++)
        {
            Edges[i] = new List<E>();
        }

        for (int i = 0; i < N - 1; i++)
        {
            int a = sc.NextInt() - 1;
            int b = sc.NextInt() - 1;
            long c = sc.NextLong();
            Edges[a].Add(new E(a, b, c));
            Edges[b].Add(new E(b, a, c));
        }
Cost = new long[N];
        Q = sc.NextInt();
        K = sc.NextInt() - 1;
        Search(K, -1, 0);
        var sb = new StringBuilder();
        for (int i = 0; i < Q; i++)
        {
            int x = sc.NextInt() - 1;
            int y = sc.NextInt() - 1;
            sb.AppendLine($"{Cost[x] + Cost[y]}");
        }

        Console.Write(sb.ToString());
    }

    private void Search(int i, int parent, long dist)
    {
        Cost[i] = dist;
        foreach (E e in Edges[i])
        {
            if (e.B == parent) continue;
            Search(e.B, i, dist + e.C);
        }
    }

    public static void Main(string[] args)
    {
        new Program().Solve();
    }
}

struct E
{
    public int A, B;
    public long C;

    public E(int a, int b, long c)
    {
        A = a;
        B = b;
        C = c;
    }
}

class Scanner
{
    public Scanner()
    {
        _pos = 0;
        _line = new string[0];
    }

    const char Separator = ' ';
    private int _pos;
    private string[] _line;

    #region スペース区切りで取得

    public string Next()
    {
        if (_pos >= _line.Length)
        {
            _line = Console.ReadLine().Split(Separator);
            _pos = 0;
        }

        return _line[_pos++];
    }

    public int NextInt()
    {
        return int.Parse(Next());
    }

    public long NextLong()
    {
        return long.Parse(Next());
    }

    public double NextDouble()
    {
        return double.Parse(Next());
    }

    #endregion

    #region 型変換

    private int[] ToIntArray(string[] array)
    {
        var result = new int[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = int.Parse(array[i]);
        }

        return result;
    }

    private long[] ToLongArray(string[] array)
    {
        var result = new long[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = long.Parse(array[i]);
        }

        return result;
    }

    private double[] ToDoubleArray(string[] array)
    {
        var result = new double[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = double.Parse(array[i]);
        }

        return result;
    }

    #endregion

    #region 配列取得

    public string[] Array()
    {
        if (_pos >= _line.Length)
            _line = Console.ReadLine().Split(Separator);

        _pos = _line.Length;
        return _line;
    }

    public int[] IntArray()
    {
        return ToIntArray(Array());
    }

    public long[] LongArray()
    {
        return ToLongArray(Array());
    }

    public double[] DoubleArray()
    {
        return ToDoubleArray(Array());
    }

    #endregion
}

Measured memory_bytes: 54300