/*
* @Author: RMQuan
* @Date: 2025-10-22 18:51:18
* @Last Modified by: RMQuan
* @Last Modified time: 2025-10-22 21:48:17
*/
/*idea :
*/
#include <bits/stdc++.h>
bool M1;
#define int long long
#define ll long long
#define INTMAX INT_MAX
#define INTMIN INT_MIN
#define LONGMAX LLONG_MAX
#define LONGMIN LLONG_MIN
#define fi first
#define se second
#define memfull(a,b) memset(a,b,sizeof(a));
#define endl '\n'
#define TASK "TEST"
#define file() if (fopen(TASK".inp","r")){freopen(TASK".inp","r",stdin); freopen(TASK".out","w",stdout);}
using namespace std;
const int MOD=1e9+7;
const int maxn=1e5+7;
const int inf=4e18;
const int LOG=17;
bool is_shop[maxn];
int N,Q,C,E;
vector<pair<int,int> > adj[maxn];
pair<int,int> edge[maxn];
int up[maxn][LOG+1],dp[maxn],h[maxn],mn[maxn][LOG+1],depth[maxn];
void pre_dfs_dp(int u,int p)
{
if (is_shop[u])dp[u]=depth[u];
else dp[u]=inf;
for (auto v:adj[u])
{
if (v.fi==p)continue;
h[v.fi]=h[u]+1;
depth[v.fi]=depth[u]+v.se;
pre_dfs_dp(v.fi,u);
dp[u]=min(dp[u],dp[v.fi]);
}
}
void dfs_lca(int u,int p)
{
for(auto v:adj[u])
{
if (v.fi==p)continue;
up[v.fi][0]=u;
mn[v.fi][0]=min(dp[u]-2*depth[u],dp[v.fi]-2*depth[v.fi]);
for (int i=1;i<=LOG;i++)
{
up[v.fi][i]=up[up[v.fi][i-1]][i-1];
mn[v.fi][i]=min(mn[v.fi][i-1],mn[up[v.fi][i-1]][i-1]);
}
dfs_lca(v.fi,u);
}
}
int lca(int u,int v)
{
if (h[u]<h[v])swap(u,v);
for (int i=LOG;i>=0;i--)if (h[up[u][i]]>=h[v])u=up[u][i];
if (u==v)return u;
for (int i=LOG;i>=0;i--)
{
if (up[u][i]!=up[v][i])
{
u=up[u][i];
v=up[v][i];
}
}
return up[u][0];
}
int dist(int u,int v)
{
return h[u]+h[v]-2*h[lca(u,v)];
}
int get_min(int u,int LCA)
{
if (u==LCA)
{
return dp[u]-2*depth[u];
}
int ans=inf;
int diff=h[u]-h[LCA];
for (int i=LOG;i>=0;i--)if (diff&(1<<i)){ans=min(ans,mn[u][i]);u=up[u][i];}
return ans;
}
void solve()
{
cin>>N>>C>>Q>>E;
for (int i=1;i<N;i++)
{
int x,y,w;
cin>>x>>y>>w;
adj[x].push_back({y,w});
adj[y].push_back({x,w});
edge[i]={x,y};
}
for (int i=1;i<=C;i++)
{
int x;
cin>>x;
is_shop[x]=true;
}
h[0]=-1;
pre_dfs_dp(E,0);
dfs_lca(E,0);
for (int i=1;i<N;i++)if (h[edge[i].fi]>h[edge[i].se])swap(edge[i].fi,edge[i].se);
while (Q--)
{
int block,pos,u,v;
cin>>block>>pos;
tie(u,v)=edge[block];
if (h[u]+1+dist(v,pos)!=h[pos])cout<<"escaped"<<endl;
else
{
int ans=depth[pos]+get_min(pos,v);
if (ans>=1e18)cout<<"oo"<<endl;
else cout<<ans<<endl;
}
}
}
int32_t main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
file();
solve();
bool M2;
cerr<<"-------------------------------------------------"<<endl;
cerr<<"Time : "<<clock()<<" ms"<<endl;
cerr<<"Memory : "<<abs(&M2-&M1)/1024/1024<<" MB"<<endl;
cerr<<"-------------------------------------------------"<<endl;
return 0;
}
