//#include<bits/stdc++.h>
#include<iostream>
#include<string>
#include<vector>
#include<utility>
#include<cmath>
#include<map>
#include<unordered_map>
#include<functional>
#include<queue>
#include<set>
#include<stack>
#include<iomanip>
#include<algorithm>
#include<numeric>
#include<memory>
using namespace std;
using ll = long long;
#define rep(i,n) for(ll i=0;i<(n);i++)
#define all(a)   a.begin(),a.end()
template<typename T =ll> using v = vector<T>;
template<typename T =ll> using vv = v<v<T>>;
template<typename T =ll,typename U =ll> using p = pair<T,U>;
template<typename T> T chmin(T &a,T b) {return a=min(a,b);}
template<typename T> T chmax(T &a,T b) {return a=max(a,b);}
const ll INF = (ll)1e18;
template <int MOD>
struct ModInt {
    using lint = long long;
    int val;

    // constructor
    ModInt(lint v = 0) : val(v % MOD) {
        if (val < 0) val += MOD;
    };

    // unary operator
    ModInt operator+() const { return ModInt(val); }
    ModInt operator-() const { return ModInt(MOD - val); }
    ModInt inv() const { return this->pow(MOD - 2); }

    // arithmetic
    ModInt operator+(const ModInt& x) const { return ModInt(*this) += x; }
    ModInt operator-(const ModInt& x) const { return ModInt(*this) -= x; }
    ModInt operator*(const ModInt& x) const { return ModInt(*this) *= x; }
    ModInt operator/(const ModInt& x) const { return ModInt(*this) /= x; }
    ModInt pow(lint n) const {
        auto x = ModInt(1);
        auto b = *this;
        while (n > 0) {
            if (n & 1) x *= b;
            n >>= 1;
            b *= b;
        }
        return x;
    }

    // compound assignment
    ModInt& operator+=(const ModInt& x) {
        if ((val += x.val) >= MOD) val -= MOD;
        return *this;
    }
    ModInt& operator-=(const ModInt& x) {
        if ((val -= x.val) < 0) val += MOD;
        return *this;
    }
    ModInt& operator*=(const ModInt& x) {
        val = lint(val) * x.val % MOD;
        return *this;
    }
    ModInt& operator/=(const ModInt& x) { return *this *= x.inv(); }
    //
    ModInt operator++(int) {
        auto t = *this;
        *this += 1;
        return t;
    }

    ModInt operator--(int) {
        auto t = *this;
        *this -= 1;
        return t;
    }
    ModInt operator<<(const int n){
        return ModInt(*this)*ModInt(2).pow(n);
    }
    // compare
    bool operator==(const ModInt& b) const { return val == b.val; }
    bool operator!=(const ModInt& b) const { return val != b.val; }

    // I/O
    friend std::istream& operator>>(std::istream& is, ModInt& x) noexcept { return is >> x.val; }
    friend std::ostream& operator<<(std::ostream& os, const ModInt& x) noexcept { return os << x.val; }
};

constexpr int MOD = 1e9 + 7;
using mint = ModInt<MOD>;

void a(){
   
}
void b(){
   
}

void c(){
    
}

class d{
    ll dijkstra(ll X,ll Y){
        if(dist[X]!=INF&&dist[Y]!=INF){
            return dist[X]+dist[Y];
        }

        priority_queue<p<>,v<p<>>,greater<p<>>> que;
        dist[K]=0;
        que.push(make_pair(0,K));
        while(!que.empty()){
            auto P = que.top(); que.pop();
            ll V = P.second;
            if(dist[V]<P.first) continue;
            rep(i,G[V].size()){
                auto E = G[V][i];
                if(dist[E.to]>dist[V]+E.cost){
                    dist[E.to] = dist[V]+E.cost;
                    que.push(make_pair(dist[E.to],E.to));
                }
            }
        }

        return dist[X]+dist[Y];
    }

    ll N;
    ll Q;
    ll K;
    using edge = struct{ll to,cost;};
    v<v<edge>> G;
    v<> dist;
    public:
    d(){
        cin >> N;
        G.resize(N);
        dist.resize(N,INF);
        rep(i,N-1){
            ll A,B,C;
            cin >> A >> B >> C;
            A--;
            B--;
            G[A].push_back(edge{B,C});
            G[B].push_back(edge{A,C});
        }
        
        cin >> Q >> K;
        K--;
        rep(i,Q){
            ll X,Y; cin >> X >> Y;
            X--; Y--;
            cout << dijkstra(X,Y) << endl;
        }
        
    }
};


void e(){

}

int main(){
    d();
}


Measured memory_bytes: 13932