#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
const ll mod = 1e9 + 7;
//const ll mod = 998244353;
#define REP(i,n) for(int i=0;i<(int)n;++i)
//debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){
os << "(" << v.first << ", " << v.second << ")"; return os;
}
template<class T> ostream& operator << (ostream& os, const vector<T> v){
for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << " ";} os << v[i];} return os;
}
template<class T> ostream& operator << (ostream& os, const vector<vector<T>> v){
for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << endl;} os << v[i];} return os;
}
string num2bit(ll num, ll len){
    string bit = "";
    REP(i, len){
    bit += char('0'+(num>>i & 1));
    }
    return bit;
}

struct edge{
    ll to, w;
};

using UGraph = vector<vector<int>>;
using Graph = vector<vector<edge>>;

template< typename G >
struct DoublingLowestCommonAncestor {
  // gは無向でOK 根はデフォルトでは0
  // 有向なら根付き木の形で与える
  const G &g;
  vector< int > dep;
  const int LOG;
  vector< vector< int > > table;

  DoublingLowestCommonAncestor(const G &g) : g(g), dep(g.size()), LOG(32 - __builtin_clz(g.size())) {
    table.assign(LOG, vector< int >(g.size(), -1));
  }

  void dfs(int idx, int par, int d) {
    table[0][idx] = par;
    dep[idx] = d;
    for(auto &to : g[idx]) {
      if(to != par) dfs(to, idx, d + 1);
    }
  }

  void build() {
    dfs(0, -1, 0);
    for(int k = 0; k + 1 < LOG; k++) {
      for(int i = 0; i < (int)table[k].size(); i++) {
        if(table[k][i] == -1) table[k + 1][i] = -1;
        else table[k + 1][i] = table[k][table[k][i]];
      }
    }
  }

  int query(int u, int v) {
    if(dep[u] > dep[v]) swap(u, v);
    for(int i = LOG - 1; i >= 0; i--) {
      if(((dep[v] - dep[u]) >> i) & 1) v = table[i][v];
    }
    if(u == v) return u;
    for(int i = LOG - 1; i >= 0; i--) {
      if(table[i][u] != table[i][v]) {
        u = table[i][u];
        v = table[i][v];
      }
    }
    return table[0][u];
  }
};

vector<ll> dist(101010, 0);

void dfs(ll now, ll par, ll d, Graph &G){
    dist[now] = d;
    for(auto e: G[now]){
        if(e.to == par) continue;
        dfs(e.to, now, d+e.w, G);
    }
    return;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    ll N;
    cin >> N;
    //UGraph H(N);
    Graph G(N);
    
    REP(i, N-1){
        ll a, b, c;
        cin >> a >> b >> c;
        a--, b--;
        //H[a].push_back(b);
        //H[b].push_back(a);
        G[a].push_back((edge){b, c});
        G[b].push_back((edge){a, c});
    }

    //DoublingLowestCommonAncestor<UGraph> lca(H);
    //lca.build();

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

    dfs(K, -1, 0, G);

    while(Q--){
        ll x, y;
        cin >> x >> y;
        x--, y--;
        cout << dist[x] + dist[y] << endl;
    }

    return 0;
}

Measured memory_bytes: 15872