#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
using i64 = long long;
const int MAXN = 1e5 + 5;
const int LOGN = 20;
const i64 oo64 = 1e18 + 5;
struct edge {
int u, v, w;
edge(int u = 0, int v = 0, int w = 0) : u(u), v(v), w(w) {}
};
int N, S, Q, E;
edge e[MAXN];
vector<pii> adj[MAXN];
int shop[MAXN];
bool is_shop[MAXN];
i64 dist[MAXN];
int depth[MAXN];
int par[MAXN];
int chainID[MAXN];
int chainHead[MAXN];
int curChain = 0;
int curPos = 0;
int pos[MAXN];
int tour[MAXN];
int sz[MAXN];
int bigC[MAXN];
i64 RMQ[MAXN][LOGN];
i64 minn[MAXN];
i64 tot = 0;
void DFS(int u, int p) {
par[u] = p;
sz[u] = 1;
depth[u] = depth[p] + 1;
minn[u] = (is_shop[u] ? dist[u] : oo64);
for(auto [v, w] : adj[u]) {
if(v == p) continue;
dist[v] = dist[u] + w;
DFS(v, u);
minn[u] = min(minn[u], minn[v]);
sz[u] += sz[v];
if(sz[bigC[u]] < sz[v]) bigC[u] = v;
}
}
void HLD(int u, int p) {
if(chainHead[curChain] == 0)
chainHead[curChain] = u;
chainID[u] = curChain;
tour[++curPos] = u;
pos[u] = curPos;
if(bigC[u] != 0)
HLD(bigC[u], u);
for(auto [v, w] : adj[u]) {
if(v == p or v == bigC[u]) continue;
curChain++;
HLD(v, u);
}
}
int LCA(int u, int v) {
while(chainID[u] != chainID[v]) {
if(chainID[u] > chainID[v]) u = par[chainHead[chainID[u]]];
else v = par[chainHead[chainID[v]]];
}
return (depth[u] < depth[v] ? u : v);
}
i64 get_dist(int u, int v) {
return dist[u] + dist[v] - 2LL * dist[LCA(u, v)];
}
i64 get_min(int l, int r) {
int b = 31 - __builtin_clz(r - l + 1);
return min(RMQ[l][b], RMQ[r - (1 << b) + 1][b]);
}
signed main() {
#define TASK "code"
if (fopen(TASK ".inp", "r")) {
freopen(TASK ".inp", "r", stdin);
freopen(TASK ".out", "w", stdout);
}
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> N >> S >> Q >> E;
for(int i = 1; i < N; i++) {
auto &[u, v, w] = e[i];
cin >> u >> v >> w;
tot += w;
adj[u].emplace_back(v, w);
adj[v].emplace_back(u, w);
}
for(int i = 1; i <= S; i++) {
cin >> shop[i];
is_shop[shop[i]] = true;
}
DFS(E, 0);
HLD(E, 0);
for(int i = 1; i < N; i++) {
auto &[u, v, w] = e[i];
if(depth[u] > depth[v]) swap(u, v);
}
// for(int i = 1; i <= N; i++) cerr << i << " " << minn[i] - 2 * dist[i] << "\n";
for(int i = 1; i <= N; i++) RMQ[pos[i]][0] = minn[i] - 2 * dist[i];
// for(int i = 1; i <= N; i++) cerr << tour[i] << "\n";
for(int j = 1; j < LOGN; j++) {
for(int i = 1; i + (1 << j) - 1 <= N; i++)
RMQ[i][j] = min(RMQ[i][j - 1], RMQ[i + (1 << (j - 1))][j - 1]);
}
while(Q--) {
int I, R;
cin >> I >> R;
const auto [u, v, w] = e[I];
if(get_dist(R, v) + get_dist(u, E) + w != get_dist(R, E)) {
cout << "escaped\n";
} else {
// cout << "skip\n";
i64 ans = dist[R];
i64 res = oo64;
while(chainID[R] != chainID[v]) {
// cout << pos[chainHead[chainID[R]]] << " " << pos[R] << "\n";
res = min(res, get_min(pos[chainHead[chainID[R]]], pos[R]));
R = par[chainHead[chainID[R]]];
}
res = min(res, get_min(pos[v], pos[R]));
if(res > tot) cout << "oo";
else cout << ans + res;
cout << "\n";
}
}
return (0 ^ 0);
}
/**
5 2 3 1
1 2 3
1 3 2
3 4 1
3 5 2
2
4
2 2
2 5
4 5
**/
/**
10 2 5 4
7 2 3
4 8 3
9 10 1
6 7 3
9 2 3
10 1 2
8 2 2
5 2 1
3 8 2
8
7
2 1
1 5
8 4
6 2
7 7
**/
