#pragma GCC optimize ("Ofast")
#include<bits/stdc++.h>
using namespace std;
void *wmem;
char memarr[96000000];
template<class T> inline void walloc1d(T **arr, int x, void **mem = &wmem){
  static int skip[16] = {0, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
  (*mem) = (void*)( ((char*)(*mem)) + skip[((unsigned long long)(*mem)) & 15] );
  (*arr)=(T*)(*mem);
  (*mem)=((*arr)+x);
}
inline void rd(int &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = getchar_unlocked();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = getchar_unlocked();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
inline void wt_L(char a){
  putchar_unlocked(a);
}
inline void wt_L(long long x){
  int s=0;
  int m=0;
  char f[20];
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    putchar_unlocked('-');
  }
  while(s--){
    putchar_unlocked(f[s]+'0');
  }
}
struct graph{
  int N;
  int *es;
  int **edge;
  void setEdge(int N__, int M, int A[], int B[], void **mem = &wmem){
    int i;
    N = N__;
    walloc1d(&es, N, mem);
    walloc1d(&edge, N, mem);
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      es[A[i]]++;
      es[B[i]]++;
    }
    for(i=(0);i<(N);i++){
      walloc1d(&edge[i], es[i], mem);
    }
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      edge[A[i]][es[A[i]]++] = B[i];
      edge[B[i]][es[B[i]]++] = A[i];
    }
  }
}
;
template<class T> struct wgraph{
  int N;
  int *es;
  int **edge;
  T **cost;
  graph g;
  void setEdge(int N__, int M, int A[], int B[], T C[], void **mem = &wmem){
    int i;
    N = N__;
    walloc1d(&es, N, mem);
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      es[A[i]]++;
      es[B[i]]++;
    }
    walloc1d(&edge, N, mem);
    for(i=(0);i<(N);i++){
      walloc1d(&edge[i], es[i], mem);
    }
    walloc1d(&cost, N, mem);
    for(i=(0);i<(N);i++){
      walloc1d(&cost[i], es[i], mem);
    }
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      edge[A[i]][es[A[i]]] = B[i];
      edge[B[i]][es[B[i]]] = A[i];
      cost[A[i]][es[A[i]]++] = C[i];
      cost[B[i]][es[B[i]]++] = C[i];
    }
    g.N = N;
    g.es = es;
    g.edge = edge;
  }
  template<class S> void getDistForest(int root, S res[], S unreachable = -1, void *mem = wmem){
    int i;
    int j;
    int k;
    int*q;
    int s;
    int z;
    char *r;
    walloc1d(&q,N,&mem);
    walloc1d(&r,N,&mem);
    for(i=(0);i<(N);i++){
      r[i]=0;
    }
    res[root]=0;
    r[root]=1;
    s=0;
    z=1;
    q[0]=root;
    while(z){
      i=q[s++];
      z--;
      for(j=(0);j<(es[i]);j++){
        k=edge[i][j];
        if(r[k]){
          continue;
        }
        res[k]=res[i]+cost[i][j];
        r[k]=1;
        q[s+z++]=k;
      }
    }
    for(i=(0);i<(N);i++){
      if(!r[i]){
        res[i]=unreachable;
      }
    }
  }
}
;
int N;
int A[100000];
int B[100000];
int C[100000];
int Q;
int K;
int X;
int Y;
long long d[100000];
int main(){
  int KL2GvlyY;
  wmem = memarr;
  wgraph<int> g;
  rd(N);
  {
    int Lj4PdHRW;
    for(Lj4PdHRW=(0);Lj4PdHRW<(N-1);Lj4PdHRW++){
      rd(A[Lj4PdHRW]);A[Lj4PdHRW] += (-1);
      rd(B[Lj4PdHRW]);B[Lj4PdHRW] += (-1);
      rd(C[Lj4PdHRW]);
    }
  }
  rd(Q);
  rd(K);K += (-1);
  g.setEdge(N,N-1,A,B,C);
  g.getDistForest(K,d);
  for(KL2GvlyY=(0);KL2GvlyY<(Q);KL2GvlyY++){
    rd(X);X += (-1);
    rd(Y);Y += (-1);
    wt_L(d[X]+d[Y]);
    wt_L('\n');
  }
  return 0;
}
// cLay varsion 20190921-1

// --- original code ---
// int N, A[1d5], B[1d5], C[1d5], Q, K, X, Y;
// ll d[1d5];
// {
//   wgraph<int> g;
//   rd(N,(A--,B--,C)(N-1),Q,K--);
//   g.setEdge(N,N-1,A,B,C);
//   g.getDistForest(K,d);
//   rep(Q){
//     rd(X--,Y--);
//     wt(d[X]+d[Y]);
//   }
// }


Measured memory_bytes: 11520