#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FOR(I, L, R) for(int I(L) ; I <= (int)R ; ++I)
#define FOD(I, R, L) for(int I(R) ; I >= (int)L ; --I)
#define FOA(I, A) for(auto &I : A)
#define print(A,L,R) FOR(OK, L, R){if(A[OK]<=-oo / 10||A[OK]>=oo)cout<<"- ";else cout<<A[OK]<<' ';}cout<<'\n';
#define prints(A) FOA(OK, A){cout<<OK<<' ';}cout << '\n';
#define printz(A,L,R) FOR(OK, 0, L){FOR(KO, 0, R){if(A[OK][KO]>-oo&&A[OK][KO]<oo)cout<<A[OK][KO]<<' ';else cout << "- ";} cout << '\n';}cout << '\n';
#define fs first
#define sd second
#define ii pair<int,int>
#define iii pair<int, ii>
#define all(A) A.begin(), A.end()
#define quickly cin.tie(0) -> ios_base::sync_with_stdio(0);
const int N = 1e5 + 5;
const int mod = 1e9 + 7;
const int oo = 1e18;
int n, q, s, root, el;
int h[N], st[N], en[N], ans[N];
bool vis[N];
ii edge[N];
vector<ii> g[N], query[N];
struct Segment_tree{
int sg[N << 2], lazy[N << 2];
void push_down(int id, int l, int r){
if(lazy[id]){
sg[id << 1] += lazy[id];
sg[id << 1 | 1] += lazy[id];
lazy[id << 1] += lazy[id];
lazy[id << 1 | 1] += lazy[id];
lazy[id] = 0;
}
}
void update(int id, int l, int r, int u, int v, int val){
if(l > v || r < u){
return;
}
if(u <= l && r <= v){
sg[id] += val;
lazy[id] += val;
return;
}
push_down(id, l, r);
int mid = (l + r) >> 1;
update(id << 1, l, mid, u, v, val);
update(id << 1 | 1, mid + 1, r, u, v, val);
sg[id] = min(sg[id << 1], sg[id << 1 | 1]);
}
int get(int id, int l, int r, int u, int v){
if(l > v || r < u){
return oo;
}
if(u <= l && r <= v){
return sg[id];
}
push_down(id, l, r);
int mid = (l + r) >> 1;
return min(get(id << 1, l, mid, u, v), get(id << 1 | 1, mid + 1, r, u, v));
}
} sg;
void DFS(int u, int par){
st[u] = ++el;
FOA(e, g[u]){
int v = e.fs;
int w = e.sd;
if(v == par){
continue;
}
h[v] = h[u] + w;
DFS(v, u);
}
en[u] = el;
}
void REROOT(int u, int par){
FOA(i, query[u]){
int v = i.fs, in = i.sd;
ans[in] = sg.get(1, 1, n, st[v], en[v]);
}
FOA(e, g[u]){
int v = e.fs;
int w = e.sd;
if(v == par){
continue;
}
sg.update(1, 1, n, st[v], en[v], -w);
sg.update(1, 1, n, 1, st[v] - 1, w);
sg.update(1, 1, n, en[v] + 1, n, w);
REROOT(v, u);
sg.update(1, 1, n, st[v], en[v], w);
sg.update(1, 1, n, 1, st[v] - 1, -w);
sg.update(1, 1, n, en[v] + 1, n, -w);
}
}
signed main(){ quickly
cin >> n >> s >> q >> root;
FOR(i, 1, n - 1){
int u, v, w;
cin >> u >> v >> w;
g[u].push_back({v, w});
g[v].push_back({u, w});
edge[i] = {u, v};
}
FOR(i, 1, s){
int u; cin >> u;
vis[u] = 1;
}
DFS(root, -1);
FOR(i, 1, n){
if(vis[i]){
sg.update(1, 1, n, st[i], st[i], h[i]);
}
else{
sg.update(1, 1, n, st[i], st[i], oo);
}
}
FOR(i, 1, q){
int id, u;
cin >> id >> u;
if(st[edge[id].fs] < st[edge[id].sd]){
swap(edge[id].fs, edge[id].sd);
}
int x = edge[id].fs;
if(st[x] <= st[u] && en[u] <= en[x]){
query[u].push_back({x, i});
}
else{
ans[i] = -1;
}
}
REROOT(root, -1);
FOR(i, 1, q){
if(ans[i] == -1){
cout << "escaped\n";
}
else{
if(ans[i] >= (int)1e15){
cout << "oo\n";
}
else{
cout << ans[i] << '\n';
}
}
}
}
