#include <bits/stdc++.h>
#define fr(i, n, m) for(int i = (n); i < (m); i ++)
#define pb push_back
#define st first
#define nd second
#define pq priority_queue
#define all(x) begin(x), end(x)
#include <time.h>
#include <cmath>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int i_inf = 1e4;
const ll inf = 1e17;
const ll mod = 1000000007;
const ld eps = 1e-13;
const ld pi = 3.14159265359;
mt19937 _rand(time(NULL));
clock_t timer = clock();
const int mxn = 200005;
int n, s, q, E;
int edl[mxn], edr[mxn];
vector<pii> g[mxn];
bool shop[mxn];
int sz[mxn];
int pos[mxn];
int temp_pos = 0;
ll dist[mxn];
int sparse[mxn][20];
int depth[mxn];
int id[mxn];
void dfs(int u, int p){
id[temp_pos] = u;
pos[u] = temp_pos++;
sz[u] = 1;
sparse[u][0] = p;
fr(i, 1, 20) sparse[u][i] = sparse[sparse[u][i-1]][i-1];
for(auto e : g[u]){
if(e.st == p) continue;
depth[e.st] = depth[u]+1;
dist[e.st] = dist[u]+e.nd;
dfs(e.st, u);
sz[u] += sz[e.st];
}
}
int lca(int a, int b){
int d = min(depth[a], depth[b]);
for(int i = 19; i >= 0; i --){
if(depth[a]-(1<<i)>= d) a = sparse[a][i];
if(depth[b]-(1<<i)>= d) b = sparse[b][i];
}
if(a == b) return a;
for(int i = 19; i >= 0; i --){
if(sparse[a][i] != sparse[b][i]){
a = sparse[a][i];
b = sparse[b][i];
}
}
return sparse[a][0];
}
ll seg[4*mxn];
ll zet[4*mxn];
void build(int k, int l, int r){
if(l == r){
seg[k] = dist[id[l]];
return;
}
int mid = (l+r)/2;
build(k*2, l, mid);
build(k*2+1, mid+1, r);
seg[k] = min(seg[k*2], seg[k*2+1]);
}
void update(int k, int l, int r, int x, int y, int z, int val){
zet[k] += z;
if(y < l || r < x) return;
if(x <= l && r <= y){
zet[k] += val;
return;
}
int mid = (l+r)/2;
update(k*2, l, mid, x, y, zet[k], val);
update(k*2+1, mid+1, r, x, y, zet[k], val);
zet[k] = 0;
seg[k] = min(seg[k*2]+zet[k*2], seg[k*2+1]+zet[k*2+1]);
}
ll query(int k, int l, int r, int x, int y, int z){
zet[k] += z;
if(y < l || r < x) return inf;
if(x <= l && r <= y){
return seg[k]+zet[k];
}
int mid = (l+r)/2;
ll ret = min(query(k*2, l, mid, x, y, zet[k]), query(k*2+1, mid+1, r, x, y, zet[k]));
zet[k] = 0;
seg[k] = min(seg[k*2]+zet[k*2], seg[k*2+1]+zet[k*2+1]);
return ret;
}
vector<int> Q[mxn];
ll ans[mxn];
int ed[mxn];
void dfs2(int u, int p){
for(auto i : Q[u]){
int q = ed[i];
int a=edl[q], b = edr[q];
if(depth[a] > depth[b]) swap(a, b);
if(lca(b, u) != b){
ans[i] = -1;
continue;
}
ans[i] = query(1, 0, n-1, pos[b], pos[b]+sz[b]-1, 0);
}
for(auto e : g[u]){
if(e.st == p) continue;
int l = pos[e.st];
int r = pos[e.st]+sz[e.st]-1;
update(1, 0, n-1, 0, n-1, 0, e.nd);
update(1, 0, n-1, l, r, 0, -2*e.nd);
dfs2(e.st, u);
update(1, 0, n-1, 0, n-1, 0, -e.nd);
update(1, 0, n-1, l, r, 0, +2*e.nd);
}
}
void solve(){
cin >> n >> s >> q >> E;
--E;
fr(i, 0, n-1){
int u, v, w;
cin >> u >> v >> w;
--u, --v;
g[u].pb({v, w});
g[v].pb({u, w});
edl[i] = u, edr[i] = v;
}
fr(i, 0, s){
int c;
cin >> c;
--c;
shop[c] = true;
}
dfs(E, E);
fr(i, 0, n){
if(shop[i]) continue;
dist[i] = inf;
}
build(1, 0, n-1);
fr(i, 0, q){
int e, u;
cin >> e >> u;
--e, --u;
ed[i] = e;
Q[u].pb(i);
}
dfs2(E, E);
fr(i, 0, q){
if(ans[i] == -1) cout<<"escaped"<<endl;
else if(ans[i] >= inf/2) cout<<"oo"<<endl;
else cout<<ans[i]<<endl;
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
solve();
}
