#include <bits/stdc++.h>
#define pii pair<int, int>
#define fi first
#define se second
#define ll long long
#define LSO(o) ((o) & -(o))
using namespace std;
int n, s, q, e, bc;
const int N = 1e5+5, C = 35;
const ll M = 1e17;
bool sh[N];
pii cel[N];
vector<pii> graf[N];
ll tcul[N], sdp[N][C];
int par[N][C];
int tme = 0, tin[N], tout[N];
void et(int v, int p)
{
tin[v] = ++tme;
for(auto x: graf[v])
if(x.fi != p) et(x.fi, v);
tout[v] = ++tme;
}
ll dfsul(int v, int p)
{
if(sh[v]) tcul[v] = 0;
for(auto x: graf[v])
if(x.fi != p)
tcul[v] = min(tcul[v], dfsul(x.fi, v)+x.se);
return tcul[v];
}
void dfs(int v, int p, int d)
{
par[v][0] = p;
sdp[v][0] = d;
for(int k=1; k<C; k++)
par[v][k] = par[par[v][k-1]][k-1],
sdp[v][k] = sdp[v][k-1] + sdp[par[v][k-1]][k-1];
for(auto x: graf[v])
if(x.fi != p)
dfs(x.fi, v, x.se);
}
ll bm(int v, int u)
{
int l = 0, r = n;
while(l < r)
{
int m = ((l+r)>>1);
// cout << '*' << l << ' ' << r << ' ' << m << '\n';
int mm = m, p = v;
// cout << '=' << p << ' ';
while(mm)
{
int z = __builtin_ctz(mm);
mm -= LSO(mm);
p = par[p][z];
// cout << p << ' ';
}
// cout << '\n';
if(tin[u] <= tin[p] && tout[p] <= tout[u])
l = m+1;
else
r = m;
}
r = l-1;
l = 0;
ll d = M;
while(l < r)
{
int m = ((l+r)>>1);
int m1 = m, m2 = m+1, p1 = v, p2 = v;
ll d1 = 0, d2 = 0;
while(m1)
{
int z = __builtin_ctz(m1);
m1 -= LSO(m1);
d1 += sdp[p1][z];
p1 = par[p1][z];
}
while(m2)
{
int z = __builtin_ctz(m2);
m2 -= LSO(m2);
d2 += sdp[p2][z];
p2 = par[p2][z];
}
d1 += tcul[p1];
d2 += tcul[p2];
if(d1 < d2)
r = m,
d = d1;
else
l = m+1,
d = d2;
}
return d;
}
int main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
for(int i=0; i<N; i++) tcul[i] = M;
memset(par, e, sizeof par);
cin >> n >> s >> q >> e;
for(int i=1; i<n; i++)
{
int u, v, w; cin >> u >> v >> w;
cel[i] = {u, v};
graf[u].push_back({v, w});
graf[v].push_back({u, w});
}
for(int i=0; i<s; i++)
{
int c; cin >> c;
sh[c] = 1;
}
et(e, 0);
dfsul(e, 0);
dfs(e, e, 0);
// for(int i=1; i<=n; i++)
// {
// cout << i << ": ";
// for(int k=0; k<5; k++)
// cout << sdp[i][k] << ' ';
// cout << '\n';
// }
while(q--)
{
int r; cin >> bc >> r;
int u = cel[bc].fi, v = cel[bc].se;
if(tin[u] < tin[v] && tout[v] < tout[u])
{
if(tin[v] <= tin[r] && tout[r] <= tout[v])
{
ll aaa = bm(r, v);
if(aaa == M) cout << "oo\n";
else cout << aaa << '\n';
}
else cout << "escaped\n";
}
else
{
if(tin[u] <= tin[r] && tout[r] <= tout[u])
{
ll aaa = bm(r, u);
if(aaa == M) cout << "oo\n";
else cout << aaa << '\n';
}
else cout << "escaped\n";
}
}
return 0;
}
