#include <bits/stdc++.h>
using namespace std;
int main(){
  int N, M, X;
  cin >> N >> M >> X;
  vector<int> A(N), B(N);
  for (int i = 0; i < N; i++){
    cin >> A[i] >> B[i];
    B[i]--;
  }
  int K;
  cin >> K;
  vector<int> C(K);
  for (int i = 0; i < K; i++){
    cin >> C[i];
  }
  vector<vector<int>> A2(M);
  for (int i = 0; i < N; i++){
    A2[B[i]].push_back(A[i]);
  }
  for (int i = 0; i < M; i++){
    sort(A2[i].begin(), A2[i].end(), greater<int>());
    if (!A2[i].empty()){
      A2[i][0] += X;
    }
  }
  vector<int> P;
  for (int i = 0; i < M; i++){
    int cnt = A2[i].size();
    for (int j = 0; j < cnt; j++){
      P.push_back(A2[i][j]);
    }
  }
  sort(P.begin(), P.end(), greater<int>());
  vector<long long> S(N + 1);
  S[0] = 0;
  for (int i = 0; i < N; i++){
    S[i + 1] = S[i] + P[i];
  }
  long long ans = 0;
  for (int i = 0; i < K; i++){
    ans += S[C[i]];
  }
  cout << ans << endl;
}