#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <cctype>
#include <cassert>
#include <climits>
#include <string>
#include <bitset>
#include <cfloat>
#include <unordered_set>
#pragma GCC optimize("Ofast")
using namespace std;
typedef long double ld;
typedef long long int ll;
typedef unsigned long long int ull;
typedef vector<int> vi;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef vector<string> vs;
typedef vector<ll> vll;
typedef vector<pair<int,int> > vpii;
typedef vector<vector<int> > vvi;
typedef vector<vector<char> > vvc;
typedef vector<vector<string> > vvs;
typedef vector<vector<ll> > vvll;
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define irep(it, stl) for(auto it = stl.begin(); it != stl.end(); it++)
#define drep(i,n) for(int i = (n) - 1; i >= 0; --i)
#define fin(ans) cout << (ans) << '\n'
#define STLL(s) strtoll(s.c_str(), NULL, 10)
#define mp(p,q) make_pair(p, q)
#define pb(n) push_back(n)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define Sort(a) sort(a.begin(), a.end())
#define Rort(a) sort(a.rbegin(), a.rend())
#define MATHPI acos(-1)
#define itn int;
#define endl '\n';
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
template <class T> inline bool chmax(T& a,T b){if(a<b){a=b;return 1;} return 0;}
template <class T> inline bool chmin(T& a,T b){if(a>b){a=b;return 1;} return 0;}
inline string getline(){string s; getline(cin,s); return s;}
inline void yn(const bool b){b?fin("yes"):fin("no");}
inline void Yn(const bool b){b?fin("Yes"):fin("No");}
inline void YN(const bool b){b?fin("YES"):fin("NO");}
struct io{io(){ios::sync_with_stdio(false);cin.tie(0);}};
const int INF = INT_MAX;
const ll LLINF = 1LL<<60;
const ll MOD = 1000000007;
const double EPS = 1e-9;

class DIJKSTRA {
public:
    ll V;

    struct dk_edge {
        ll to;
        ll cost;
    };

    typedef pair<ll, ll> PI; //firstは最短距離、secondは頂点の番号
    vector<vector<dk_edge> >G;
    vector<ll> d; //これ答え。d[i]:=V[i]までの最短距離
    vector<ll> prev; //経路復元

    DIJKSTRA(ll size) {
        V = size;
        G = vector<vector<dk_edge> >(V);
        prev = vector<ll> (V, -1);
    }

    void add(ll from, ll to, ll cost) {
        dk_edge e = {to, cost};
        G[from].push_back(e);
    }

    void dijkstra(ll s) {
        //greater<P>を指定することでfirstが小さい順に取り出せるようにする
        priority_queue<PI, vector<PI>, greater<PI> > que;
        d = vector<ll> (V, LLINF);
        d[s] = 0;
        que.push(PI(0, s));

        while(!que.empty()) {
            PI p = que.top();
            que.pop();
            ll v = p.second;
            if(d[v] < p.first) continue;
            for(ll i = 0; i < G[v].size(); i++) {
                dk_edge e = G[v][i];
                if(d[e.to] > d[v] + e.cost) {
                    d[e.to] = d[v] + e.cost;
                    prev[e.to] = v;
                    que.push(PI(d[e.to], e.to));
                }
            }
        }
    }
};

int main() {
    
    ll n;
    cin>>n;
    DIJKSTRA dk(n);
    rep(i,n-1){
        ll a,b,c;
        cin>>a>>b>>c;
        a--;b--;
        dk.add(a,b,c);
        dk.add(b,a,c);
    }

    ll q,k;
    cin>>q>>k;
    k--;
    dk.dijkstra(k);
    rep(i,q){
        ll x,y;
        cin>>x>>y;
        x--;y--;
        cout<<dk.d[x]+dk.d[y]<<endl;
    }


}



Measured memory_bytes: 11888