#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
//const bool debug = false;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
long long op(long long  a, long long  b) { return a + b; }
long long  e() { return 0; }
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, m, x; cin >> n >> m >> x;
	map<int, vector<long long>>mp;
	rep(i, n) {
		int a, b; cin >> a >> b;
		mp[b].push_back(a);
	}
	vector<long long>v;
	for (auto p : mp) {
		auto pv = p.second;
		sort(allR(pv));
		rep(i, pv.size()) {
			if (0 == i)v.push_back(pv[i] + x);
			else v.push_back(pv[i]);
		}
	}
	sort(allR(v));
	segtree<long long, op, e>seg(v);
	long long ans = 0;
	int k; cin >> k;
	rep(i, k) {
		int c; cin >> c;
		ans += seg.prod(0, c);
	}
	cout << ans << endl;
	return 0;
}