#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int DY[]{1, 0, -1, 0}, DX[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1}, DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  int n, m, x; cin >> n >> m >> x;
  map<int, vector<int>> a;
  REP(_, n) {
    int ai, b; cin >> ai >> b;
    a[b].emplace_back(ai);
  }
  vector<int> problem;
  for (auto it = a.begin(); it != a.end(); it = next(it)) {
    sort(ALL(it->second), greater<int>());
    it->second.front() += x;
    copy(ALL(it->second), back_inserter(problem));
  }
  sort(ALL(problem), greater<int>());
  vector<int> solve(n, 0);
  int k; cin >> k;
  solve[0] = k;
  while (k--) {
    int c; cin >> c;
    if (c < n) --solve[c];
  }
  FOR(i, 1, n) solve[i] += solve[i - 1];
  ll ans = 0;
  REP(i, n) ans += 1LL * problem[i] * solve[i];
  cout << ans << '\n';
  return 0;
}