/*
* @Author: hungeazy
* @Date: 2024-10-16 08:23:59
* @Last Modified by: hungeazy
* @Last Modified time: 2024-10-16 13:32:20
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
using namespace std;
using namespace __gnu_pbds;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define int long long
#define ll long long
#define ull unsigned long long
#define sz(x) x.size()
#define sqr(x) (1LL * (x) * (x))
#define all(x) x.begin(), x.end()
#define fill(f,x) memset(f,x,sizeof(f))
#define FOR(i,l,r) for(int i=l;i<=r;i++)
#define FOD(i,r,l) for(int i=r;i>=l;i--)
#define debug(x) cout << #x << " = " << x << '\n'
#define ii pair<int,int>
#define iii pair<int,ii>
#define di pair<ii,ii>
#define vi vector<int>
#define vii vector<ii>
#define mii map<int,int>
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define fi first
#define se second
#define pb push_back
#define MOD 1000000007
#define __lcm(a,b) (1ll * ((a) / __gcd((a), (b))) * (b))
#define YES cout << "YES\n"
#define NO cout << "NO\n"
#define MASK(i) (1LL << (i))
#define c_bit(i) __builtin_popcountll(i)
#define BIT(x,i) ((x) & MASK(i))
#define SET_ON(x,i) ((x) | MASK(i))
#define SET_OFF(x,i) ((x) & ~MASK(i))
#define oo 1e18
#define name "LANDSLIDE"
#define endl '\n'
#define time() cerr << endl << "-------------Time:" << 1000.0 * clock() / CLOCKS_PER_SEC << "ms.";
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
const int N = (int)1e5+10;
int n,S,Q,H,a[N];
iii edge[N];
namespace sub12 {
vii g[N];
int d[N];
bool approved()
{
return n <= 1e3 and Q <= 1e3;
}
void BFS(int p)
{
FOR(i,1,n) d[i] = oo;
d[p] = 0;
priority_queue<ii,vii,greater<ii>> q;
q.push({0,p});
while (!q.empty())
{
int u = q.top().se, cost = q.top().fi;
q.pop();
if (cost > d[u]) continue;
for (ii x : g[u])
{
int v,w;
tie(v,w) = x;
if (d[v] > d[u]+w)
{
d[v] = d[u]+w;
q.push({d[v],v});
}
}
}
}
void solve(void)
{
while (Q--)
{
int I,R;
cin >> I >> R;
FOR(i,1,n) g[i].clear();
FOR(i,1,n-1)
if (i != I)
{
int u = edge[i].fi, v = edge[i].se.fi, w = edge[i].se.se;
g[u].pb({v,w}); g[v].pb({u,w});
}
BFS(R);
if (d[H] != oo) cout << "escaped" << endl;
else
{
int ans = oo;
FOR(i,1,S) minimize(ans,d[a[i]]);
if (ans == oo) cout << "oo" << endl;
else cout << ans << endl;
}
}
}
}
namespace sub345 {
int h[N],in[N],out[N],cnt=0,dem[N];
bool check[N];
vii g[N];
struct Node {
int len,mn,par;
} f[N][20];
void DFS(int u, int p)
{
in[u] = ++cnt;
if (check[u]) dem[u] = 1;
else f[u][0].mn = oo;
for (ii x : g[u])
{
int v,w;
tie(v,w) = x;
if (v == p) continue;
h[v] = h[u]+1;
f[v][0].par = u;
f[v][0].len = w;
DFS(v,u);
dem[u] += dem[v];
minimize(f[u][0].mn,f[v][0].mn+w);
}
out[u] = cnt;
}
void init()
{
FOR(j,1,log2(n))
FOR(i,1,n)
{
f[i][j].par = f[f[i][j-1].par][j-1].par;
f[i][j].len = f[i][j-1].len+f[f[i][j-1].par][j-1].len;
f[i][j].mn = min(f[i][j-1].mn,f[f[i][j-1].par][j-1].mn+f[i][j-1].len);
}
}
void solve(void)
{
FOR(i,1,n-1)
{
int u = edge[i].fi, v = edge[i].se.fi, w = edge[i].se.se;
g[u].pb({v,w}); g[v].pb({u,w});
}
FOR(i,1,S) check[a[i]] = true;
DFS(H,-1);
init();
// FOR(i,1,n) cout << in[i] << " " << out[i] << endl;
while (Q--)
{
int I,R;
cin >> I >> R;
int u = edge[I].fi, v = edge[I].se.fi;
if (h[u] > h[v]) swap(u,v);
if (in[R] >= in[v] and in[R] <= out[v])
{
if (!dem[v]) cout << "oo" << endl;
else
{
int len = 0, ans = oo;
FOD(i,log2(n),0)
if (h[f[R][i].par] >= h[v])
{
minimize(ans,f[R][i].mn+len);
len += f[R][i].len;
R = f[R][i].par;
}
cout << min(ans,f[R][0].mn+len) << endl;
}
}
else cout << "escaped" << endl;
}
}
}
signed main()
{
fast;
if (fopen(name".inp","r"))
{
freopen(name".inp","r",stdin);
freopen(name".out","w",stdout);
}
cin >> n >> S >> Q >> H;
FOR(i,1,n-1)
{
int u,v,w;
cin >> u >> v >> w;
edge[i] = {u,{v,w}};
}
FOR(i,1,S) cin >> a[i];
// if (sub12::approved()) sub12::solve();
// else
sub345::solve();
time();
return 0;
}
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