#include <bits/stdc++.h>
#define pb push_back
#define f first
#define s second
#define dbg(x) cout << "reached here " << x << endl;
#define int long long
using namespace std;
typedef pair<int, int> pii;
struct edge {int o, d, w, id;};
const int maxn = 1e5+5, inf = (int)100000*100000*100000;
int dis[maxn], E, st[maxn], ft[maxn], t = 1;
vector<edge> adj[maxn];
edge yal[maxn];
void dfs(int v, int par)
{
st[v] = t;
t++;
for (auto e: adj[v])
{
int u = e.o^e.d^v;
if(u != par)
{
dis[u] = dis[v] + 1;
dfs(u, v);
}
}
ft[v] = t;
t++;
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, s, q;
cin >> n >> s >> q >> E;
for (int i = 1; i <= n-1; ++i)
{
cin >> yal[i].o >> yal[i].d >> yal[i].w;
yal[i].id = i;
adj[yal[i].o].pb(yal[i]);
adj[yal[i].d].pb(yal[i]);
}
for (int i = 1; i <= s; ++i)
{
int a;
cin >> a;
}
dfs(E, 0);
while(q--)
{
int l, r;
cin >> l >> r;
int v = yal[l].o;
if(dis[yal[l].o] < dis[yal[l].d])
v = yal[l].d;
if(st[r] >= st[v] and ft[r] <= ft[v])
cout << 0 << endl;
else
cout << "escaped" << endl;
}
return 0;
}
