#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define MOD 1000000007
#define MOD2 998244353
#define INF 1000000007
#define LINF 1000000000000000007LL
#define PI 3.14159265359
#define P pair<ll,ll>
template <typename T>
inline bool chmax(T &a, const T &b){
  if(a<b) {a=b; return true;}
  else return false;
}
template <typename T>
inline bool chmin(T &a, const T &b){
  if(a>b) {a=b; return true;}
  else return false;
}
struct Edge{
  int to; ll cost;
  Edge(int to, ll cost) : to(to), cost(cost) {}
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;
void add_edge(Graph &g,int from,int to,ll cost,bool rev,ll rev_cost){
  g[from].push_back(Edge(to,cost));
  if(rev) g[to].push_back(Edge(from,rev_cost));
}



void solve(){
  int n,m,x;
  cin>>n>>m>>x;
  vector<int> a(n),b(n);
  rep(i,n){
    cin>>a[i]>>b[i];
    b[i]--;
  }
  int k;
  cin>>k;
  vector<int> c(k);
  rep(i,k) cin>>c[i];
  //----------------------------------------
  vector<vector<int>> kind(m);
  rep(i,n){
    kind[b[i]].push_back(a[i]);
  }
  vector<int> points;
  rep(i,m){
    if(kind[i].size()){
      sort(kind[i].begin(),kind[i].end(),greater<int>());
      kind[i][0]+=x;
    }
    for(auto p : kind[i]) points.push_back(p);
  }
  sort(points.begin(),points.end(),greater<int>());
  vector<int> solved(n+1);
  solved[0]=k;
  rep(i,k) solved[c[i]+1]--;
  rep(i,n) solved[i+1]+=solved[i];
  ll ans=0;
  rep(i,n) ans += solved[i+1]*points[i];
  cout<<ans<<'\n';
}

int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout<<setprecision(10)<<fixed;
  solve();
  return 0;
}