/*
** TASK:
** LINK:
*/
#include <bits/stdc++.h>
#define ll long long
#define pii pair<ll, ll>
#define st first
#define nd second
#define file "test"
using namespace std;
const long long INF = 1e18;
const long long N = 2e5 + 5;
struct edge {
ll u, v, w, id;
} g[N];
ll n, s, q, e, shop[N], up[20][N], h[N], dpUp[20][N], f[N], dp[N];
vector <int> d[N];
void dfs(int p, int u) {
for (int i: d[u]) {
int v = g[i].u ^ g[i].v ^ u, w = g[i].w;
if (v == p) continue;
g[i].u = u; g[i].v = v;
h[v] = h[u] + 1; up[0][v] = u; f[v] = f[u] + w;
dfs(u, v);
dp[u] = min(dp[u], dp[v] + w);
}
for (int i: d[u]) { int v = g[i].u ^ g[i].v ^ u, w = g[i].w;
if (v == p) continue;
dpUp[0][v] = dp[u] - f[u];
}
}
int jump(int u, int k) {
for (int i = 19; i >= 0; i --) if ((k >> i) & 1) u = up[i][u];
return u;
}
bool isANC(int p, int u) {
int delta = h[u] - h[p];
return jump(u, delta) == p;
}
ll get(int u, int k) {
ll ans = INF;
for (int i = 19; i >= 0; i --) if ((k >> i) & 1) {
ans = min(ans, dpUp[i][u]);
u = up[i][u];
}
return ans;
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> s >> q >> e;
for (int i = 1; i < n; i ++) {
cin >> g[i].u >> g[i].v >> g[i].w;
g[i].id = i;
d[g[i].u].push_back(i);
d[g[i].v].push_back(i);
}
for (int i = 0; i < 20; i ++)
for (int j = 1; j <= n; j ++)
dpUp[i][j] = INF;
for (int i = 1, x; i <= s; i ++)
cin >> x, shop[x] = true;
for (int i = 1; i <= n; i ++)
if (shop[i]) dp[i] = 0; else dp[i] = INF;
// "e" is root
dfs(e, e);
for (int i = 1; i < 20; i ++)
for (int j = 1; j <= n; j ++) {
up[i][j] = up[i - 1][up[i - 1][j]];
dpUp[i][j] = min(dpUp[i - 1][j], dpUp[i - 1][up[i - 1][j]]);
}
int I, R;
while (q --) {
cin >> I >> R;
int u = g[I].u, v = g[I].v;
if (!isANC(v, R)) {
cout << "escaped\n";
continue;
}
if (dp[v] == INF) {
cout << "oo\n";
continue;
}
cout << min(f[R] + get(R, h[R] - h[v]), dp[R]) << '\n';
}
return 0;
}
/** /\_/\
* (= ._.)
* / >🍵 \>🍮
**/
