#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(v) v.begin(),v.end()
typedef long long ll;
 
#include<bits/stdc++.h>
using namespace std;

int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  
  ll n,m,x;
  cin>>n>>m>>x;
  vector<ll> A(n),B(n);
  rep(i,n) cin>>A[i]>>B[i];
  int k;
  cin>>k;
  vector<int> C(k);
  rep(i,k) cin>>C[i];
  
  vector<pair<ll,ll>> D(n);
  rep(i,n) D[i]={A[i],B[i]};
  sort(ALL(D));
  reverse(ALL(D));
  
  priority_queue<pair<ll,ll>> que;
  vector<int> check(m+1);
  
  vector<ll> E,F;
  rep(i,n){
    ll a=D[i].first,b=D[i].second;
    if(check[b]==0){
      while(!que.empty() && que.top().first>a+x){
        auto t=que.top();
        que.pop();
        E.push_back(t.first),F.push_back(t.second);
      }
      check[b]=1;
      E.push_back(a),F.push_back(b);
    }
    else que.push({a,b});
  }
  while(!que.empty()){
    auto t=que.top();
    que.pop();
    E.push_back(t.first),F.push_back(t.second);
  }
  
  vector<ll> G(m+1),S(n+1);
  rep(i,n){
    S[i+1]=S[i]+E[i];
    if(G[F[i]]==0){
      S[i+1]+=x;
      G[F[i]]=1;
    }
  }
  ll ans=0;
  rep(i,k) ans+=S[C[i]];
  cout<<ans<<endl;
    
  return 0;
}