/* -*- coding: utf-8 -*-
 *
 * 1708.cc:  No.1708 Quality of Contest - yukicoder
 */

#include<cstdio>
#include<queue>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 200000;
const int MAX_M = 200000;

/* typedef */

typedef long long ll;
typedef queue<int> qi;
typedef pair<int,int> pii;

/* global variables */

pii ps[MAX_N];
bool used[MAX_M];
ll ss[MAX_N + 1];

/* subroutines */

/* main */

int main() {
  int n, m, x;
  scanf("%d%d%d", &n, &m, &x);

  for (int i = 0; i < n; i++) {
    int ai, bi;
    scanf("%d%d", &ai, &bi);
    bi--;
    ps[i] = pii(ai, bi);
  }
  sort(ps, ps + n, greater<pii>());

  qi q;
  for (int i = 0, j = 0; i < n; i++) {
    while (j < n && used[ps[j].second]) q.push(ps[j++].first);

    int v0 = (j < n) ? (ps[j].first + x) : 0;
    int v1 = (! q.empty()) ? q.front() : 0;

    if (v0 > v1) {
      ss[i + 1] = ss[i] + v0;
      used[ps[j].second] = true;
      j++;
    }
    else {
      ss[i + 1] = ss[i] + v1;
      q.pop();
    }
  }
  //for (int i = 0; i <= n; i++) printf("%lld ", ss[i]); putchar('\n');

  int k;
  scanf("%d", &k);

  ll sum = 0;
  for (int i = 0; i < k; i++) {
    int ci;
    scanf("%d", &ci);
    sum += ss[ci];
  }

  printf("%lld\n", sum);
  return 0;
}