// Original C++ solution (slower):
#include <vector>

#include <iostream>

#include <cmath>

#include <map>

#include <unordered_map>

#include <algorithm>

#include <fstream>

#include <unistd.h>

#include <string>

#include <numeric>

#include <queue>

#include <deque>

#include <sstream>

#include <iomanip>

#include <set>

#include <stack>

#include <cassert>

using namespace std;

typedef long long ll;

typedef vector<int> vi;

typedef vector<ll> vl;

typedef vector<vl> vvl;

typedef vector<vvl> vvvl;

typedef vector<vi> vvi;

typedef vector<vvi> vvvi;

typedef vector<bool> vb;

typedef vector<vector<bool>> vvb;

typedef vector<string> vs;

typedef vector<vector<string>> vvs;

typedef vector<char> vc;

typedef vector<vector<char>> vvc;

typedef vector<double> vd;

typedef vector<vd> vvd;

typedef vector<vvd> vvvd;

typedef pair<int, int> P;

typedef pair<ll, ll> PL;

typedef vector<P> vp;

typedef vector<PL> vpl;

typedef vector<vector<P>> vvp;

typedef vector<vector<PL>> vvpl;

const int INF = 1001001001;

const ll LINF = 1e16;

const double pi = 3.1415926535897932;

const string endstr = "\n";

#define FOR(i, a, b) for(ll i = (a); i < b; i++)

#define REP(i, n) for(ll i = 0; i < n; i++)

#define FORMAP(it, m) for(auto it = m.begin(); it != m.end(); it++)

#define ff first

#define ss second

#define pb push_back



template <typename T>

T gcd(T a, T b) {

    return (a == 0) ? b : gcd(b%a, a);

}

template <typename T>

T lcm(T a, T b) {

    return a / gcd(a, b) * b;

}



bool p_comp_fs(const PL p1, const PL p2){ return p1.first < p2.first;};

bool p_comp_fg(const PL p1, const PL p2){ return p1.first > p2.first;};

bool p_comp_ss(const PL p1, const PL p2){ return p1.second < p2.second;};

bool p_comp_sg(const PL p1, const PL p2){ return p1.second > p2.second;};

template <typename T>

vector<T> uniquen(vector<T> vec){

    vec.erase(unique(vec.begin(), vec.end()), vec.end());

    return vec;

}



const ll lim = 100100;

using edge = struct{ll to; ll cost;};

vector<edge> tree[lim];

ll depth[lim];



void dfs(ll ver, ll par, ll dep){

    depth[ver] = dep;

    for (auto& e : tree[ver]) {

        if(e.to == par) continue;

        dfs(e.to, ver, dep+e.cost);

    }

}



int main(){

    int N; cin >> N;

    REP(i, N-1){

        ll a, b, c; cin >> a >> b >> c; a--; b--;

        tree[a].pb({b,c});

        tree[b].pb({a,c});

    }

    ll Q, K; cin >> Q >> K;

    K--;

    dfs(K, -1, 0);

    REP(i, Q){

        ll x, y; cin >> x >> y; x--; y--;

        cout << depth[x] + depth[y] << endl;

    }

    return 0;

}


// Optimized solution to the same problem (faster):
#include <vector>

#include <iostream>

#include <cmath>

#include <map>

#include <unordered_map>

#include <algorithm>

#include <fstream>

#include <unistd.h>

#include <string>

#include <numeric>

#include <queue>

#include <deque>

#include <sstream>

#include <iomanip>

#include <set>

#include <stack>

#include <cassert>

using namespace std;

typedef long long ll;

typedef vector<int> vi;

typedef vector<ll> vl;

typedef vector<vl> vvl;

typedef vector<vvl> vvvl;

typedef vector<vi> vvi;

typedef vector<vvi> vvvi;

typedef vector<bool> vb;

typedef vector<vector<bool>> vvb;

typedef vector<vvb> vvvb;

typedef vector<vvvb> vvvvb;

typedef vector<string> vs;

typedef vector<vector<string>> vvs;

typedef vector<char> vc;

typedef vector<vector<char>> vvc;

typedef vector<double> vd;

typedef vector<vd> vvd;

typedef vector<vvd> vvvd;

typedef pair<int, int> P;

typedef pair<ll, ll> PL;

typedef vector<P> vp;

typedef vector<PL> vpl;

typedef vector<vector<P>> vvp;

typedef vector<vector<PL>> vvpl;

const int INF = 1001001001;

const ll LINF = 1e17;

const double pi = 3.1415926535897932;

const string endstr = "\n";

#define FOR(i, a, b) for(ll i = (a); i < b; i++)

#define RFOR(i, a, b) for(ll i = (a); i > b; i--)

#define REP(i, n) for(ll i = 0; i < n; i++)

#define RREP(i, n) for(ll i = n-1; i > -1; i--)

#define FORMAP(it, m) for(auto it = m.begin(); it != m.end(); it++)

#define ff first

#define ss second

#define pb push_back

#define epb emplace_back



template <typename T>

T gcd(T a, T b) {

    return (a == 0) ? b : gcd(b%a, a);

}

template <typename T>

T lcm(T a, T b) {

    return a / gcd(a, b) * b;

}



bool p_comp_fs(const PL p1, const PL p2){ return p1.first < p2.first;};

bool p_comp_fg(const PL p1, const PL p2){ return p1.first > p2.first;};

bool p_comp_ss(const PL p1, const PL p2){ return p1.second < p2.second;};

bool p_comp_sg(const PL p1, const PL p2){ return p1.second > p2.second;};

template <typename T>

vector<T> uniquen(vector<T> vec){

    vec.erase(unique(vec.begin(), vec.end()), vec.end());

    return vec;

}



struct edge {ll to, cost;};



int main(){

    ll N; cin >> N;

    vector<edge> ed[N];

    REP(i, N-1){

        ll a, b, c; cin >> a >> b >> c; a--; b--;

        ed[a].pb({b,c});

        ed[b].pb({a,c});

    }

    ll Q, K; cin >> Q >> K;

    K--;

    queue<ll> q; q.push(K);

    vl dist(N, LINF); dist[K] = 0;

    while(!q.empty()){

        ll now = q.front(); q.pop();

        for(auto e : ed[now]){

            if(dist[e.to] != LINF) continue;

            if(dist[e.to] > dist[now] + e.cost){

                dist[e.to] = dist[now] + e.cost;

                q.push(e.to);

            }

        }

    }

    

    REP(i, Q){

        ll x, y; cin >> x >> y; x--; y--;

        cout << dist[x] + dist[y] << endstr;

    }

    return 0;

}


// Fastest known solution for this problem: