#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fbo find_by_order
#define ook order_of_key
typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector<int> vi;
typedef long double ld;
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update> pbds;
typedef set<ll>::iterator sit;
typedef map<ll,ll>::iterator mit;
vector<vi> edges;
ll dist[6111][6111];
int n,m,q,L;
vector<pair<ii,int> > adj[2111];
vi belong[6111];
int getid(int a, int b)
{
return (a*2+b);
}
const ll INF=ll(1e18);
int a[211111];
ll dp[2][6111];
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
cin>>n>>m>>q>>L;
for(int i=0;i<m;i++)
{
int u,v,w; cin>>u>>v>>w; u--; v--; edges.pb({u,v});
adj[u].pb(mp(mp(v,w),i)); adj[v].pb(mp(mp(u,w),i));
}
int orim = m;
for(int i=0;i<n;i++)
{
adj[n].pb(mp(mp(i,0),m++)); edges.pb({n,i});
}
for(int i=0;i<m;i++)
{
for(int j=0;j<2;j++)
{
belong[edges[i][j]].pb(getid(i,j));
priority_queue<ii,vector<ii>,greater<ii> > pq;
int s = getid(i,j);
pq.push(mp(0,s));
for(int k=0;k<m*2;k++) dist[s][k] = INF;
dist[s][s] = 0;
while(!pq.empty())
{
ll d=pq.top().fi; int u = pq.top().se; pq.pop();
//cerr<<"DIST : "<<s<<' '<<u<<' '<<d<<'\n';
int vertex = edges[u/2][u%2]; int edgeno = u/2;
for(auto k:adj[vertex])
{
int v = k.fi.fi; ll w = k.fi.se; int id = k.se;
if(id==edgeno) continue;
int vid = id*2;
if(edges[id][0]!=v) vid++;
if(dist[s][vid]>d+w)
{
dist[s][vid] = d + w;
pq.push(mp(dist[s][vid], vid));
}
}
}
}
}
for(int i=0;i<L;i++)
{
cin>>a[i]; a[i]--;
}
for(int zz=0;zz<q;zz++)
{
int y,z; cin>>y>>z; y--; z--; a[y]=z;
for(int i=0;i<m*2;i++)
{
dp[0][i] = INF;
}
/*
for(int i=0;i<m;i++)
{
for(int j=0;j<2;j++)
{
if(edges[i][j]==a[0])
{
dp[0][getid(i,j)] = 0;
}
}
}
*/
dp[0][getid(orim + a[0],1)] = 0;
for(int i=0;i+1<L;i++)
{
int pre = i&1; int cur = pre^1;
for(int j=0;j<m*2;j++)
{
dp[cur][j] = INF;
}
for(int j=0;j<m*2;j++)
{
if(dp[pre][j]<INF)
{
ll v=dp[pre][j];
for(int k:belong[a[i+1]])
{
if(dist[j][k]<INF)
{
dp[cur][k] = min(dp[cur][k], v + dist[j][k]);
}
}
}
}
}
ll mn = INF;
for(int i=0;i<m*2;i++)
{
mn = min(mn, dp[(L+1)&1][i]);
}
if(mn>=INF) mn=-1;
cout<<mn<<'\n';
}
}
