#include <vector>
#include <iostream>
#include <cmath>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <fstream>
#include <unistd.h>
#include <string.h>
#include <string>
#include <numeric>
#include <queue>
#include <deque>
#include <sstream>
#include <iomanip>
#include <set>
#include <stack>
#include <cassert>
#include <functional>
#include <random>
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<vvvl> vvvvl;
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<vs> vvs;
typedef vector<vvs> vvvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<vvd> vvvd;
typedef pair<ll, ll> PL;
typedef vector<PL> vpl;
typedef vector<vector<PL>> vvpl;
typedef vector<vvpl> vvvpl;
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
#define ALL(X) (X).begin(),(X).end()

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){
    sort(ALL(vec));
    vec.erase(unique(vec.begin(), vec.end()), vec.end());
    return vec;
}

inline ll popcnt(ll x){return __builtin_popcountll((unsigned long long)x);};
template<class T> bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }
//friend bool operator<(const stc& lhs, const stc& rhs){
//    return std::tie(lhs.l, lhs.r) < std::tie(rhs.l, rhs.r);
//}

const ll size = 100100;
const ll MX_LOG = 20;
vpl G[size];
ll par[MX_LOG][size];
ll depth[size];
ll dist[size];

void dfs(ll v, ll p, ll d, ll distance){
    depth[v] = d;
    dist[v] = distance;
    par[0][v] = p;
    for(PL c : G[v]){
        if(c.ff == p) continue;
        dfs(c.ff, v, d+1, distance + c.ss);
    }
}

void init(ll root){
    dfs(root, -1, 0, 0);
    rep(k, MX_LOG-1) rep(v, size){
        if(par[k][v] < 0) par[k+1][v] = -1;
        else par[k+1][v] = par[k][par[k][v]];
    }
}

ll lca(ll u, ll v){
    if(depth[u] > depth[v]) swap(u, v);
    ll dd = depth[v] - depth[u];
    rep(k, MX_LOG) {
        if(dd >> k & 1) v = par[k][v];
    }
    if(u == v) return u;
    
    for(ll k = MX_LOG-1; k >= 0; k--){
        if(par[k][u] != par[k][v]){
            u = par[k][u];
            v = par[k][v];
        }
    }
    return par[0][u];
}


int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ll N; cin >> N;
    rep(_, N-1){
        ll a, b, c; cin >> a >> b >> c; a--; b--;
        G[a].pb({b, c}); G[b].pb({a, c});
    }
    
    ll Q, K; cin >> Q >> K; K--;
    init(K);
    rep(_, Q){
        ll x, y; cin >> x >> y; x--; y--;
        ll r = lca(x, y);
        if(r == K){
            cout << dist[x] + dist[y] << endstr;
        }
        else{
            cout << dist[x] + dist[y] - 2*dist[K] << endstr;
        }
    }
    return 0;
}


Measured memory_bytes: 32256