/*
IN THE NAME OF GOD
*/
#include <bits/stdc++.h>
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
typedef pair<int, pii> ipii;
typedef pair<pii, int> piii;
typedef pair<ll, pll> lpll;
typedef pair<pll, ll> plll;
typedef pair<pii, pii> piipii;
typedef pair<pll, pll> pllpll;
typedef long double ld;
#define SQ 350
#define endl '\n'
#define F first
#define S second
#define Mp make_pair
#define pb push_back
#define pf push_front
#define PQ priority_queue
#define size(x) ((ll)x.size())
#define DASH "---------"
#define UNDERLINE "_________"
#define all(x) (x).begin(),(x).end()
#define FORD(i, s, e) for(int i=s; i>=e; --i)
#define FOR(i, s, e) for(int i=s; i<=e; ++i)
#define kill(x) cout << x << '\n', exit(0);
#define set_dec(x) cout << fixed << setprecision(x);
#define ios ios_base::sync_with_stdio(false), cin.tie(0)
#define fuck(x) cout << "(" << #x << " , " << x << ")" << endl
#define file_io(x,y) freopen(x, "r", stdin); freopen(y, "w", stdout);
const int _N = 232323, _LG=131072, _lg=18;
const ll _MOD = 1e9+7, INF=1e15; // 998244353
ll getmod(ll a, ll mod=_MOD) {return (a+3*mod)%mod;}
ll max(ll a, ll b) {return (a>b ? a : b);}
ll min(ll a, ll b) {return (a<b ? a : b);}
ll abso(ll a) {return (a<0?-a:a);}
int n, S, Q, E, tin[_N], tout[_N], t, Shop[_N], ind, par[_N][_lg+1], I, R, h[_N];
ll dp[_N][_lg+1], dist[_N][_lg+1];
vector<pll> adj[_N];
pll Ed[_N];
void getEdge() {
ll v,u,w;
cin>>v>>u>>w;
adj[v].pb({u, w});
adj[u].pb({v, w});
Ed[++ind]={v,u};
}
void dfs(int v=E, int p=0, ll EW=INF) {
dist[v][0]=EW, par[v][0]=p, tin[v]=++t;
dp[v][_lg] = (Shop[v] ? 0 : INF);
FOR(i,1,_lg-1) {
par[v][i]=par[par[v][i-1]][i-1], dist[v][i]=dist[v][i-1]+dist[par[v][i-1]][i-1];
}
dp[v][0] = min(dp[v][_lg], EW+dp[p][_lg]);
FOR(i,1,_lg-1) {
dp[v][i] = min(dp[v][i-1], dist[v][i-1] + dp[par[v][i-1]][i-1]);
}
for(auto it : adj[v]) {
if(it.F!=p) {
h[it.F]=h[v]+1;
dfs(it.F, v, it.S);
dp[v][_lg] = min(dp[v][_lg], dp[it.F][_lg]+it.S);
}
}
tout[v]=++t;
}
int main () {
ios;
cin>>n>>S>>Q>>E; h[E]=1;
FOR(i,1,n-1) {getEdge();}
FOR(i,1,S) {int C;cin>>C;Shop[C]=1;}
FOR(i,0,_lg) {dp[0][i]=dist[0][i]=INF;}
dfs();
FOR(q,1,Q) {
cin>>I>>R;
if(!(tin[Ed[I].F]<=tin[R] && tout[Ed[I].F]>=tout[R] && tin[Ed[I].S]<=tin[R] && tout[Ed[I].S]>=tout[R])) {
cout<<"escaped\n"; continue;
}
int root=(h[Ed[I].F] > h[Ed[I].S] ? Ed[I].F : Ed[I].S);
ll ans=dp[R][_lg], tmp=0;
FORD(i,_lg-1,0) {
if(h[par[R][i]]>=h[root] && par[R][i]!=0) {
ans=min(dp[R][i]+tmp, ans);tmp+=dist[R][i];R=par[R][i];
}
}
if(ans>=INF || ans<0) {cout<<"oo\n";}
else {cout<<ans<<endl;}
}
return 0;
}
