#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll=long long;
using Graph=vector<vector<int>>;
#define INF 1000000000
#define MOD 998244353
#define MAX 200000

int main(){
  int N,M;
  ll X;
  cin>>N>>M>>X;
  vector<vector<ll>> A(M);
  for(int i=0;i<N;i++){
    ll a;
    int b;
    cin>>a>>b;
    b--;
    A[b].push_back(a);
  }
  vector<ll> B;
  for(int i=0;i<M;i++){
    if(A[i].size()==0){
      continue;
    }
    sort(A[i].begin(),A[i].end(),greater<ll>());
    B.push_back(A[i][0]+X);
    for(int j=1;j<A[i].size();j++){
      B.push_back(A[i][j]);
    }
  }
  sort(B.begin(),B.end(),greater<ll>());
  vector<ll> sum(N+1,0);
  for(int i=0;i<N;i++){
    sum[i+1]=sum[i]+B[i];
  }
  ll ans=0;
  int K;
  cin>>K;
  for(int i=0;i<K;i++){
    int C;
    cin>>C;
    ans+=sum[C];
  }
  cout<<ans<<'\n';
}