#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, b, a) for (int i = (b), _a = (a); i >= _a; i--)
#define BIT(mask,i) ((mask >> i) & 1ll )
#define endl '\n'
#define all(x) x.begin(),x.end()
#define ii pair <int,int>
using namespace std;
template<class X, class Y>bool minimize(X &x, const Y &y) {if (x > y) {x = y;return true;} else return false;}
template<class X, class Y>bool maximize(X &x, const Y &y) {if (x < y) {x = y;return true;} else return false;}
const long long oo = 1e18;
const int N = 1e5+5;
const int MOD = 1e9+7;
vector <ii> g[N];
int h[N];
int p[N][25];
int ns[N][25];
int sum[N];
int n,s,q;
ii ed[N];
int lca(int u,int v)
{
if (h[u] > h[v]) swap(u,v);
int gap = h[v] - h[u];
FOR(k,0,23)
{
if (BIT(gap,k))
{
v = p[v][k];
}
}
if ( v== u) return u;
FORD(k,23,0)
{
if (p[u][k] != p[v][k])
{
u = p[u][k];
v = p[v][k];
}
}
return p[u][0];
}
void dfs(int u,int par)
{
h[u] = h[par] + 1;
p[u][0] = par;
for(auto [v,w]:g[u])
{
if (v == par) continue;
sum[v] = sum[u] + w;
dfs(v,u);
ns[u][0] = min(ns[u][0],ns[v][0] + w);
}
}
void Whyalwaysmezzz()
{
int rot;
cin >> n >> s >> q >> rot;
FOR(i,1,n-1)
{
int u,v,w;
cin >> u>> v >> w;
ed[i] = {u,v};
g[u].push_back({v,w});
g[v].push_back({u,w});
}
FOR(i,1,n) ns[i][0] = oo;
FOR(i,1,s)
{
int lmqzzz;
cin >> lmqzzz;
ns[lmqzzz][0] = 0;
}
// p[rot][0] = rot;
dfs(rot,rot);
FOR(k,1,23)
{
FOR(i,1,n)
{
p[i][k] = p[p[i][k-1]][k-1];
ns[i][k] = min(ns[i][k-1],ns[p[i][k-1]][k-1] + sum[i] - sum[p[i][k-1]]);
}
}
while (q--)
{
int x , r;
cin >> x >> r;
auto [u,v] = ed[x];
if (h[u] < h[v]) u = v;
if (lca(r,u) != u)
{
cout << "escaped" << endl;
continue;
}
int gap = h[r] - h[u]+1;
int ans = oo;
int tmp = r;
FOR(k,0,20)
{
if (BIT(gap,k))
{
int kc = sum[tmp] - sum[r];
ans = min(ans , kc + ns[r][k]);
r = p[r][k];
}
}
if (ans >= oo) cout << "oo" << endl;
else cout << ans << endl;
}
return;
}
#define TASK "task"
signed main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);//freopen(TASK".inp","r",stdin);freopen(TASK".out","w",stdout);
int Sty1e = 1;
// cin >> Sty1e;
while (Sty1e--) Whyalwaysmezzz();
return 0;
}
