// #include <bits/stdc++.h> #include <iostream> #include <cmath> #include <algorithm> #include <map> #include <unordered_map> #include <vector> #include <iomanip> #include <string> #include <queue> #include <set> #include <deque> using namespace std; #define int long long #define endl "\n" #define fi first #define se second const int M=1e9+7; const int inf = 1e14; const int LOG=17; const int N=1e5+5; int n , m , c , w , k , t=1 , q=1 , x , y , z , l , r; vector<pair<int,int>>a[N]; map<pair<int,int>,int>in; map<int,pair<int,int>>it; int sh[N]; int dp[LOG][N]; int di[N]; int vi[N]; int av[N]; int p[LOG][N]; int li[LOG][N]; void makest(){ for (int j=1;j<LOG;j++){ for (int i=1;i<=n;i++){ p[j][i]=p[j-1][p[j-1][i]]; } } } int bl(int x,int d){ int k=LOG-1; while (k>=0){ if ((1<<k)<=d){ d-=1<<k; x=p[k][x]; } k--; } return x; } void dfs(int x,int y){ for (auto [i,w]:a[x]){ if (i==y)continue; dfs(i,x); dp[0][x]=min(dp[0][x],dp[0][i]+w); } } void makst(){ for (int j=1;j<LOG;j++){ for (int i=1;i<=n;i++){ li[j][i]=li[j-1][i]+li[j-1][p[j-1][i]]; } } for (int j=1;j<LOG;j++){ for (int i=1;i<=n;i++){ dp[j][i]=min(dp[j-1][i],dp[j-1][p[j-1][i]]+li[j-1][i]); } } } int dis(int x,int d){ int k=LOG-1; int c=0; int ans=inf; while (k>=0){ if (d>=(1<<k)){ ans=min(ans,c+dp[k][x]); c+=li[k][x]; x=p[k][x]; d-=1<<k; } k--; } ans=min(ans,c+dp[0][x]); return ans; } void solve(){ int s,q,e; cin >> n >> s >> q >> e; for (int i=0;i<n-1;i++){ cin >> x >> y >> w; a[x].push_back({y,w}); a[y].push_back({x,w}); in[{x,y}]=i; in[{y,x}]=i; it[i]={x,y}; } for (int i=1;i<=n;i++){ dp[0][i]=inf; } for (int i=0;i<s;i++){ cin >> x; sh[x]=1; dp[0][x]=0; } queue<int>o; o.push(e); vi[e]=1; di[e]=1; while (o.size()){ int h=o.front(); o.pop(); for (auto [i,w]:a[h]){ if (vi[i])continue; vi[i]=1; di[i]=di[h]+1; li[0][i]=w; p[0][i]=h; o.push(i); } } makest(); dfs(e,0); for (int i=1;i<=n;i++){ if (dp[0][i]<inf){ av[i]=1; } vi[i]=0; } makst(); // cout << dis(5,1) << endl; for (int i=0;i<q;i++){ int j,k; cin >> k >> j; k--; x=it[k].fi,y=it[k].se; if (di[x]>di[y])swap(x,y); if (di[y]>di[j]){ cout << "escaped" << endl; continue; } if (bl(j,di[j]-di[y])!=y or bl(j,di[j]-di[x])!=x){ cout << "escaped" << endl; continue; } if (av[y]){ cout << dis(j,di[j]-di[y]) << endl; } else{ cout << "oo" << endl; } } } signed main() { // #ifndef ONLINE_JUDGE // freopen("input.txt","r" ,stdin); // freopen("output.txt","w",stdout); // #endif ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE cin.tie(0), cout.tie(0);//DO NOT USE IN INTERACTIVE cout << fixed << setprecision(9); srand(time(0)); // int t=1; // cin >> t; for (int _=1;_<=t;_++){ solve(); q++; } }