#include <bits/stdc++.h>
using namespace std;
#ifdef DEBUG
#include "../Library/debug.h"
#else
#define dbg(x...)
#endif
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) for (int i = 0; i < (a); ++i)
#define FORd(i, a, b) for (int i = (b) - 1; i >= (a); --i)
#define F0Rd(i, a) for (int i = (a) - 1; i >= 0; --i)
#define trav(a, x) for (auto& a : x)
#define f first
#define s second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) x.begin(), x.end()
const char nl = '\n';
const int INF = 1e9;
const int MOD = 1e9 + 7;
void solve(){
int n, s, q, e;
cin >> n >> s >> q >> e; --e;
vector<vi> adj(n);
vector<array<int, 3>> edge(n - 1);
vector<bool> shop(n);
F0R(i, n - 1){
int a, b, w;
cin >> a >> b >> w;
a--, b--;
edge[i][0] = a ^ b;
edge[i][1] = w;
adj[a].pb(i);
adj[b].pb(i);
}
F0R(i, s){
int a;
cin >> a; --a;
shop[a] = true;
}
vi depth(n), par(n);
par[e] = -1;
auto dfs = [&](auto self, int u, int p) -> void{
trav(id, adj[u]){
int v = edge[id][0] ^ u;
if(v == p) continue;
edge[id][2] = v;
par[v] = id;
depth[v] = depth[u] + 1;
self(self, v, u);
}
};
dfs(dfs, e, -1);
vl dist(n);
auto dfs_dist = [&](auto self, int u, int p, ll d) -> void{
dbg(u, p, d)
dist[u] = d;
trav(id, adj[u]){
int v = edge[id][0] ^ u;
if(v == p) continue;
self(self, v, u, d + edge[id][1]);
}
};
dfs_dist(dfs_dist, e, -1, 0);
vl mn(n);
auto dfs_mn = [&](auto self, int u, int p) -> void{
if(shop[u])
mn[u] = dist[u];
else mn[u] = 1e18;
trav(id, adj[u]){
int v = edge[id][0] ^ u;
if(v == p) continue;
self(self, v, u);
mn[u] = min(mn[u], mn[v]);
}
};
dfs_mn(dfs_mn, e, -1);
F0R(i, n) if(mn[i] != 1e18)
mn[i] -= 2 * dist[i];
// vl cost_subtree(n, 1e18);
// {
// priority_queue<array<ll, 3>> pq;
// F0R(i, n){
// if(shop[i]){
// pq.push({depth[i], 0, i});
// cost_subtree[i] = 0;
// }
// }
// while(!pq.empty()){
// auto [depth_, cost, u] = pq.top();
// pq.pop();
// cost *= -1;
// int id = par[u];
// if(id == -1)
// continue;
// int p = edge[id][0] ^ u;
// if(cost_subtree[p] > cost_subtree[u] + edge[id][1]){
// cost_subtree[p] = cost_subtree[u] + edge[id][1];
// pq.push({depth[p], -cost_subtree[p], p});
// }
// }
// }
int mxLog = 20;
vector<vi> nxt(mxLog, vi(n));
F0R(i, n)
if(par[i] == -1) nxt[0][i] = i;
else nxt[0][i] = edge[par[i]][0] ^ i;
FOR(k, 1, mxLog) F0R(i, n)
nxt[k][i] = nxt[k - 1][nxt[k - 1][i]];
// if(nxt[k - 1][i] == -1) nxt[k][i] = -1;
// else nxt[k][i] = nxt[k - 1][nxt[k - 1][i]];
auto jump_k = [&](int i, int k){
F0R(j, mxLog)
if((k >> j) & 1){
i = nxt[j][i];
// if(i == -1) return -1;
}
return i;
};
vector<vl> nxt_mn(mxLog, vl(n, 1e18));
dbg(par)
F0R(i, n) nxt_mn[0][i] = mn[edge[(par[i] == -1 ? i : par[i])][0] ^ i];
// F0R(i, n) nxt_mn[0][i] = mn[i];
FOR(k, 1, mxLog) F0R(i, n){
nxt_mn[k][i] = min(nxt_mn[k - 1][i], nxt_mn[k - 1][nxt[k - 1][i]]);
}
auto jump_mn = [&](int i, int k){
ll x = mn[i];
F0R(j, mxLog)
if((k >> j) & 1){
x = min(nxt_mn[j][i], x);
i = nxt[j][i];
}
return x;
};
// vector<vl> nxt_mindist(mxLog, vl(n));
// F0R(i, n)
// if(par[i] == -1) nxt[0][i] = 1e18;
// else nxt[0][i] = edge[par[i]][1];
// FOR(k, 1, mxLog) F0R(i, n)
// if(nxt[k][i] == -1) nxt_mindist[k][i] = 1e18;
// else nxt_mindist[k][i] = min(nxt_mindist[k - 1][nxt[k - 1][i]], nxt_mindist[k - 1][i]);
// auto jump_k_cost = [&](int i, int k) -> ll{
// ll total_cost = 0;
// F0R(j, mxLog)
// if((k >> j) & 1){
// total_cost += nxt_dist[j][i];
// i = nxt[j][i];
// if(i == -1)
// return 1e18;
// }
// return total_cost;
// };
dbg(dist)
dbg(mn)
dbg(shop)
dbg(nxt)
dbg(nxt_mn)
while(q--){
int id, x;
cin >> id >> x; --id, --x;
int y = edge[id][2];
dbg(x, y)
int diff = depth[x] - depth[y];
dbg(diff)
if(diff < 0 || (diff == 0 && x != y)){
cout << "escaped" << nl;
continue;
}
// if(x == y){
// if(cost_subtree[x] == 1e18)
// cout << "oo" << nl;
// else cout << cost_subtree[x] << nl;
// continue;
// }
int new_x = jump_k(x, diff);
dbg(new_x, y)
if(new_x != y){
cout << "escaped" << nl;
continue;
}
if(shop[x]){
cout << 0 << nl;
continue;
}
ll ans = jump_mn(x, diff);
dbg(ans, x, diff)
dbg(ans + dist[x])
if(ans == 1e18){
cout << "oo" << nl;
}
else{
cout << ans + dist[x] << nl;
}
// if(cost_subtree[new_x] == 1e18){
// cout << "oo" << nl;
// continue;
// }
// ll ans = cost_subtree[new_x] + jump_k_cost(x, diff);
// int lo = 0, hi = diff;
// while(lo <= hi){
// int m = lo + (hi - lo) / 2;
// ll aux = cost_subtree[jump_k(x, m)] + jump_k_cost(x, m);
// if(aux <=)
// }
}
}
int32_t main(){
ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
int TC = 1;
// cin >> TC;
while(TC--){
solve();
}
return 0;
}
