#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
using namespace std;
// using namespace __gnu_pbds;
#define pb push_back
#define ins insert
#define fi first
#define se second
#define endl "\n"
#define ALL(x) x.begin(), x.end()
#define intt long long
const intt mod = 1e9 + 7;
const intt base = 9973;
const intt inf = 1e18;
const intt mxN = 5e5 + 5;
const intt L = 21;
vector<vector<pair<intt,intt>>> graph, mn;
vector<vector<intt>> up;
vector<intt> in(mxN), out(mxN), sub(mxN), depth(mxN), is(mxN), cost(mxN);
vector<pair<intt,intt>> H(mxN);
intt N, S, Q, E, timer;
void dfs(intt node, intt parent){
in[node] = timer++;
up[0][node] = parent;
for(intt i = 1; i < L; i++) {
up[i][node] = up[i-1][up[i-1][node]];
}
for(auto u : graph[node]) {
if(u.fi != parent) {
depth[u.fi] = depth[node] + 1;
cost[u.fi] = cost[node] + u.se;
dfs(u.fi, node);
}
}
out[node] = timer++;
if(is[node]) {
H[node].fi = 0;
H[node].se = node;
} else {
for(auto u : graph[node]) {
if(u.fi != parent) {
if(H[node].fi > H[u.fi].fi + u.se) {
H[node].fi = H[u.fi].fi + u.se;
H[node].se = H[u.fi].se;
}
}
}
}
}
bool isata(intt a, intt b) {
return in[a] <= in[b] && out[a] >= out[b];
}
void solve() {
cin >> N >> S >> Q >> E;
graph.assign(N + 1, vector<pair<intt,intt>> {});
up.assign(L, vector<intt> (N + 1, 0ll));
mn.assign(L, vector<pair<intt,intt>> (N + 1, {inf, 0ll}));
H.assign(N + 1, {inf, 0ll});
vector<pair<intt,intt>> edge(N+1);
for(intt i = 1; i <= N - 1; i++) {
intt a, b, w;
cin >> a >> b >> w;
graph[a].pb({b, w});
graph[b].pb({a, w});
edge[i] = {a, b};
}
for(intt i = 1; i <= S; i++) {
intt node;
cin >> node;
is[node] = 1;
}
dfs(E, E);
for(intt i = 1; i <= N; i++) {
if(H[i].fi < H[up[0][i]].fi) {
mn[0][i] = H[i];
} else {
mn[0][i] = H[up[0][i]];
}
}
for(intt j = 1; j < L; j++) {
for(intt i = 1; i <= N; i++) {
if(mn[j][i].fi > mn[j-1][up[j-1][i]].fi) {
mn[j][i] = mn[j-1][up[j-1][i]];
}
}
}
while(Q--) {
intt node, idx;
cin >> idx >> node;
intt a = edge[idx].fi, b = edge[idx].se;
if(depth[a] > depth[b]) {
swap(a, b);
}
if(!isata(b, node)) {
cout << "escaped" << endl;
continue;
}
if(is[node]) {
cout << 0 << endl;
continue;
}
intt yol = depth[node] - depth[b], qaldir = node, ans = inf, nod = 0;
for(intt i = L - 1; i >= 0; i--) {
if((1 << i) & yol) {
intt mnod = mn[i][qaldir].se;
intt c = (cost[node] - cost[up[i][qaldir]]) + mn[i][qaldir].fi;
if(isata(mnod, node)) {
c = cost[node] - cost[mnod];
}
if(ans > c) {
ans = c;
nod = i;
}
qaldir = up[i][qaldir];
}
}
qaldir = node;
ans = min(ans, H[node].fi);
if(ans == inf) {
cout << "oo" << endl;
} else {
cout << ans << endl;
}
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
intt tst = 1;
// cin >> tst;
while(tst--) {
solve();
}
}
