#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define pa pair<int, int>
#define pall pair<ll, int>
#define fi first
#define se second
#define TASK "test"
#define Size(x) (int) x.size()
#define all(x) x.begin(), x.end()
using namespace std;
template<typename T1, typename T2> bool mini (T1 &a, T2 b) {if(a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2> bool maxi (T1 &a, T2 b) {if(a < b) a = b; else return 0; return 1;}
const int MOD = 1e9 + 7;
const int LOG = 20;
const int maxn = 2e5 + 7;
const ll oo = 1e18 + 69;
int n, s, q, e, u, v, w;
ll dp[maxn], f[maxn];
vector<pa> g[maxn];
bool is_shop[maxn];
pa edge[maxn];
void dfs(int u, int par) {
dp[u] = oo;
if(is_shop[u]) dp[u] = f[u];
for(auto e:g[u]) {
int v = e.fi, w = e.se;
if(v == par) continue;
f[v] = f[u] + w;
dfs(v, u);
mini(dp[u], dp[v]);
}
}
struct LCA {
int p[maxn][LOG], f[maxn];
ll mn[maxn][LOG];
void dfs(int u, int par) {
p[u][0] = par;
for(auto e:g[u]) {
int v = e.fi;
if(v == par) continue;
f[v] = f[u] + 1;
mn[v][0] = dp[v];
dfs(v, u);
}
}
ll get(int u, int v) {
if(f[u] < f[v]) swap(u, v);
int k = f[u] - f[v];
ll res = dp[u];
for(int i = 0; i < LOG; i++)
if((k >> i) & 1) {
mini(res, mn[u][i]);
u = p[u][i];
}
mini(res, dp[v]);
if(u == v) return res;
for(int i = LOG - 1; i >= 0; i--)
if(p[u][i] != p[v][i]) {
mini(res, mn[u][i]);
u = p[u][i];
mini(res, mn[v][i]);
v = p[v][i];
}
mini(res, mn[u][0]);
mini(res, mn[v][0]);
mini(res, mn[p[u][0]][0]);
return res;
}
void init() {
f[e] = 0;
mn[e][0] = dp[e];
dfs(e, 0);
for(int i = 1; i < LOG; i++) {
for(int u = 1; u <= n; u++) {
p[u][i] = p[p[u][i - 1]][i - 1];
mn[u][i] = min(mn[u][i - 1], mn[p[u][i - 1]][i - 1]);
}
}
}
bool check(int u, int v) {
int k = f[u] - f[v];
for(int i = 0; i < LOG; i++)
if((k >> i) & 1) u = p[u][i];
return (u == v);
}
} lca;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
//freopen(TASK".inp", "r", stdin);
//freopen(TASK".out", "w", stdout);
cin>>n>>s>>q>>e;
for(int i = 1; i < n; i++) {
cin>>u>>v>>w;
g[u].pb({v, w});
g[v].pb({u, w});
edge[i] = {u, v};
}
for(int i = 1; i <= s; i++) {
int x;
cin>>x;
is_shop[x] = 1;
}
f[e] = 0;
dfs(e, 0);
for(int i = 1; i <= n; i++)
if(dp[i] != oo) dp[i] -= 2LL * f[i];
lca.init();
while(q--) {
int x, id;
cin>>id>>x;
u = edge[id].fi, v = edge[id].se;
if(lca.f[u] < lca.f[v]) swap(u, v);
if(!lca.check(x, u)) {
cout<<"escaped\n";
continue;
}
ll ans = lca.get(x, u);
if(ans == oo) cout<<"oo";
else cout<<ans + f[x];
cout<<"\n";
}
return 0;
}
