using System;
using System.Collections.Generic;
using System.Linq;
using BitArray = System.Collections.BitArray;
using BigInteger = System.Numerics.BigInteger;
using TextReader = System.IO.TextReader;
using System.Text;

namespace AtCoderProject
{
    public class Program
    {
        public object Calc()
        {
            var N = consoleReader.Int;
            {
                var gb = new LengthGraphBuilder(N);
                foreach (var cr in consoleReader.Repeat(N - 1))
                    gb.Add(cr.Int - 1, cr.Int - 1, cr.Int);
                graph = gb.ToArray();
            }
            int Q = consoleReader.Int;
            K = consoleReader.Int - 1;
            distances = Enumerable.Repeat(-1L, N).ToArray();
            distances[K] = 0;
            InitDistance(K);

            return AllLines(consoleReader.Repeat(Q).Select(CalcImpl));
        }
        void InitDistance(int index)
        {
            foreach (var next in graph[index])
                if (distances[next.to] == -1)
                {
                    distances[next.to] = distances[index] + next.length;
                    InitDistance(next.to);
                }
        }
        long CalcImpl(ConsoleReader cr)
        {
            int x = cr.Int - 1, y = cr.Int - 1;
            return (distances[x] + distances[y]);
        }
        long[] distances;
        Next[][] graph;
        int K;
        struct Next
        {
            public int to;
            public int length;
        }
        class LengthGraphBuilder
        {
            public List<Next>[] lists;
            public LengthGraphBuilder(int count)
            {
                this.lists = new List<Next>[count];
                for (int i = 0; i < count; i++)
                    this.lists[i] = new List<Next>();
            }
            public LengthGraphBuilder(int count, IEnumerable<int[]> arrays) : this(count)
            {
                foreach (var item in arrays)
                    this.Add(item[0], item[1], item[2]);
            }
            public void Add(int from, int to, int length)
            {
                this.lists[from].Add(new Next { to = to, length = length });
                this.lists[to].Add(new Next { to = from, length = length }); // 有向の場合は消す
            }
            public Next[][] ToArray()
            {
                var N = this.lists.Length;
                var res = new Next[N][];
                for (int i = 0; i < N; i++)
                    res[i] = this.lists[i].ToArray();
                return res;
            }
        }


        #region いつもの
#pragma warning disable
        private ConsoleReader consoleReader;
        public Program(ConsoleReader consoleReader) { this.consoleReader = consoleReader; }
        static void Main() => Console.WriteLine(new Program(new ConsoleReader(Console.In)).Calc()); static string AllLines<T>(IEnumerable<T> source) => string.Join("\n", source);
    }
    static class Ext
    {
        public static Dictionary<TKey, int> GroupCount<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector) => source.GroupBy(keySelector).ToDictionary(g => g.Key, g => g.Count());
        public static Dictionary<TKey, int> GroupCount<TKey>(this IEnumerable<TKey> source) => source.GroupCount(i => i);
    }
    public class ConsoleReader { private string[] ReadLineSplit() => textReader.ReadLine().Split(Array.Empty<char>(), StringSplitOptions.RemoveEmptyEntries); private string[] line = Array.Empty<string>(); private int linePosition; private TextReader textReader; public ConsoleReader(TextReader tr) { textReader = tr; } public int Int => int.Parse(String); public long Long => long.Parse(String); public double Double => double.Parse(String); public string String { get { if (linePosition >= line.Length) { linePosition = 0; line = ReadLineSplit(); } return line[linePosition++]; } } public class SplitLine { private string[] splited; public SplitLine(ConsoleReader cr) { splited = cr.ReadLineSplit(); cr.line = Array.Empty<string>(); } public int[] Int => String.Select(x => int.Parse(x)).ToArray(); public int[] Int0 => String.Select(x => int.Parse(x) - 1).ToArray(); public long[] Long => String.Select(x => long.Parse(x)).ToArray(); public double[] Double => String.Select(x => double.Parse(x)).ToArray(); public string[] String => splited; } public SplitLine Split => new SplitLine(this); public class RepeatReader : IEnumerable<ConsoleReader> { ConsoleReader cr; int count; public RepeatReader(ConsoleReader cr, int count) { this.cr = cr; this.count = count; } public IEnumerator<ConsoleReader> GetEnumerator() => Enumerable.Repeat(cr, count).GetEnumerator(); System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => GetEnumerator(); public IEnumerable<string> String => this.Select(cr => cr.String); public IEnumerable<int> Int => this.Select(cr => cr.Int); public IEnumerable<int> Int0 => this.Select(cr => cr.Int - 1); public IEnumerable<long> Long => this.Select(cr => cr.Long); public IEnumerable<double> Double => this.Select(cr => cr.Double); } public RepeatReader Repeat(int count) => new RepeatReader(this, count); }
    #endregion
}


Measured memory_bytes: 49696