#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define X first
#define Y second
const int MXN = 1e5+5;
const int LOG = 17;
const ll inf = 1e18;
int par[MXN][LOG], W[MXN], n, down[MXN];
vector<pii> g[MXN];
bool shop[MXN];
ll dp[MXN], mn[MXN][LOG], h[MXN];
int stt[MXN], fnt[MXN], timer;
void dfs1(int v) {
for(int i=1; i<LOG; i++)
par[v][i] = par[par[v][i-1]][i-1];
stt[v] = timer++;
dp[v] = shop[v] ? 0 : inf;
for(auto [u, id] : g[v])
if(u!=par[v][0]) {
par[u][0] = v;
h[u] = h[v]+W[id];
down[id] = u;
dfs1(u);
dp[v] = min(dp[v], dp[u]+W[id]);
}
fnt[v] = timer++;
}
inline bool is_anc(int u, int v) {
return stt[u] <= stt[v] && fnt[v] <= fnt[u];
}
vector<pii> Q[MXN];
inline void upd(int v, ll x) {
mn[v][0] = x;
for(int i=1; i<LOG; i++)
mn[v][i] = min(mn[v][i-1], mn[par[v][i-1]][i-1]);
}
inline ll get(int v, int d) {
ll res = inf;
for(int i=0; i<LOG; i++)
if(d>>i&1)
res = min(res, mn[v][i]),
v = par[v][i];
return res;
}
ll ans[MXN];
void dfs2(int v) {
upd(v, dp[v]-h[v]);
for(auto [e, id] : Q[v])
ans[id] = get(v, h[v]-h[down[e]]+1)+h[v];
if(shop[v]) {
upd(v, -h[v]);
for(auto [u, id] : g[v])
if(u!=par[v][0])
dfs2(u);
}
else {
ll mn1 = 2*inf, mn2 = 2*inf;
for(auto [u, id] : g[v])
if(u!=par[v][0]) {
ll val = dp[u] + W[id];
if(val<mn2) mn2 = val;
if(mn2<mn1) swap(mn1, mn2);
}
for(auto [u, id] : g[v])
if(u!=par[v][0]) {
if(dp[u] + W[id] == mn1) upd(v, mn2 - h[v]);
else upd(v, mn1 - h[v]);
dfs2(u);
}
}
}
int32_t main() {
cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
int s, e, q;
cin >> n >> s >> q >> e;
for(int i=0, u,v,w; i<n-1; i++) {
cin >> u >> v >> w;
g[u].push_back({v, i+1});
g[v].push_back({u, i+1});
W[i+1] = w;
}
for(int i=0, c; i<s; i++) {
cin >> c;
shop[c] = 1;
}
dfs1(e);
for(int i=0; i<q; i++) {
int e, r;
cin >> e >> r;
if(is_anc(down[e], r))
Q[r].push_back({e, i});
else
ans[i] = -1;
}
dfs2(e);
for(int i=0; i<q; i++)
if(ans[i]==-1) cout << "escaped\n";
else if(ans[i]>=inf/10) cout << "oo\n";
else cout << ans[i] << '\n';
return 0;
}
