#include <bits/stdc++.h>
#include<bits/extc++.h>
using namespace std;
using namespace __gnu_pbds;
#define int long long
#define ll __uint128_t
#define V(x) vector<x>
#define G(x) greater<x>
#define MS(x) multiset<x>
#define BG(x) begin(x)
#define All(x) BG(x), end(x)
#define Q(x) queue<x>
#define PQ(x) priority_queue<x, V(x), G(x)>
#define PQG(x) priority_queue<x, V(x), less<x>>
#define OST(x, y) tree<x, null_type, y, rb_tree_tag,tree_order_statistics_node_update>
#define Lb lower_bound
#define Ub upper_bound
#define F first
#define S second
#define T0 get<0>
#define T1 get<1>
#define T2 get<2>
#define P(x) pair<x,x>
#define IO cin.sync_with_stdio(false); cin.tie(nullptr);
#define For(i,a,b,c) for(int i = a; i != b; i+=c)
#define lsb(x) (x&(-x))
#define PB push_back
#define Rm1(a,b) (a.erase(a.find(b)))
#define ER erase
#define Add insert
#define AE(a,b,c) a[b].PB(c)
#define AWE(a,b,c,d) a[b].PB({c,d})
#define AUE(a,b,c) AE(a,b,c), AE(a,c,b)
#define AUWE(a,b,c,d) AWE(a,b,c,d), AWE(a,c,b,d)
#define MOD 1000000007LL
#define HMOD 9999999992999999999ULL
#define FIO(a) freopen((string(a) + ".in").c_str(), "r", stdin), freopen((string(a)+".out").c_str(), "w", stdout)
#define N 100100
V(P(int)) adj[N];
P(int) roads[N];
int hc[N], sz[N], dep[N], val[N], top[N], pos[N], arr[N][20], proc, p[N];
bool shop[N];
void dfs(int n) {
sz[n] = 1;
if(!shop[n])
val[n] = 1e18;
for(auto i: adj[n]) {
if(i.F!=p[n]) {
p[i.F] = n;
dep[i.F] = dep[n]+i.S;
dfs(i.F);
if(sz[hc[n]] < sz[i.F])
hc[n] = i.F;
sz[n]+=sz[i.F];
val[n] = min(val[n], val[i.F]+i.S);
}
}
}
void dfs2(int n) {
if(n!=hc[p[n]])
top[n] = n;
else
top[n] = top[p[n]];
pos[n] = ++proc;
val[n]-=dep[n];
arr[pos[n]][0] = val[n];
if(hc[n])
dfs2(hc[n]);
for(auto i: adj[n]) {
if(i.F!=p[n]&&i.F!=hc[n]) {
dfs2(i.F);
}
}
}
int query(int l, int r){
if(l > r)
swap(l, r);
int x = 31-__builtin_clz(r-l+1);
return min(arr[l][x], arr[r-(1<<x)+1][x]);
}
signed main() {
IO;
int n, s, q, e;
cin >> n >> s >> q >> e;
For(i, 1, n, 1){
int a, b,c;
cin >> a >> b >> c;
AUWE(adj,a,b,c);
roads[i] = {a, b};
}
For(i,1,s+1,1){
int x;
cin >> x;
shop[x]=1;
}
dep[e] = 1;
dfs(e);
dfs2(e);
for(int j = 1; j < 20; j++)
for(int i = 1; i < n - (1 << j) + 2; i++)
arr[i][j] = min(arr[i][j-1], arr[i+(1<<(j-1))][j-1]);
for(int i = 0; i < q; i++){
int x, y;
cin >> y >> x;
if(dep[roads[y].F] > dep[roads[y].S])
y = roads[y].F;
else
y = roads[y].S;
int temp = x;
while(dep[p[top[temp]]] >= dep[y]) {
temp = p[top[temp]];
}
if(top[temp]!=top[y]||dep[x] < dep[y]) {
cout << "escaped\n";
} else {
int ans = 1e18, add = dep[x];
while(x!=temp) {
ans = min(ans, query(pos[top[x]], pos[x]));
x = p[top[x]];
}
ans = min(ans, query(pos[x], pos[y]));
if(ans > 1e15) {
cout << "oo\n";
} else {
cout << ans + add << '\n';
}
}
}
}
