#include <iostream>
#include <vector>
#include <algorithm>
#include <array>
#include <iterator>
#include <string>
#include <cctype>
#include <cstring>
#include <cstdlib>
#include <cassert>
#include <cmath>
#include <ctime>
#include <iomanip>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <bitset>
#include <random>
#include <utility>
#include <functional>
using namespace std;
void Main()
{
	int N,M,X;
	cin >> N >> M >> X;
	vector<int> A(N),B(N);
	vector<vector<int>> G(M);
	for(int i = 0;i < N;i++)
	{
		cin >> A[i] >> B[i];
		B[i]--;
		G[B[i]].push_back(A[i]);
	}
	int K;
	cin >> K;
	vector<int> C(N + 1);
	for(int i = 0;i < K;i++)
	{
		int c;
		cin >> c;
		C[c]++;
	}
	multiset<pair<int,int>> S,T;
	for(int i = 0;i < N;i++)
	{
		S.insert(make_pair(A[i],B[i]));
	}
	vector<int> Q;
	Q.reserve(N);
	vector<int> nw(N);
	for(int i = 0;i < N;i++)
	{
		if(T.empty())
		{
			pair<int,int> P = *S.rbegin();
			nw[i] = 1;
			Q.push_back(P.first);
			for(int a : G[P.second])
			{
				auto it = S.find(make_pair(a,P.second));
				S.erase(it);
				T.insert(make_pair(a,P.second));
			}
			T.erase(T.find(P));
		}
		else if(S.empty())
		{
			pair<int,int> P = *T.rbegin();
			Q.push_back(P.first);
			T.erase(T.find(P));
		}
		else
		{
			pair<int,int> L = *S.rbegin(),R = *T.rbegin();
			if(L.first + X > R.first)
			{
				nw[i] = 1;
				Q.push_back(L.first);
				for(int a : G[L.second])
				{
					auto it = S.find(make_pair(a,L.second));
					S.erase(it);
					T.insert(make_pair(a,L.second));
				}
				T.erase(T.find(L));
			}
			else
			{
				Q.push_back(R.first);
				T.erase(T.find(R));
			}
		}
	}
	long long ans = 0;
	int cnt = 0;
	long long sum = 0;
	for(int i = 0;i < N;i++)
	{
		if(nw[i])
		{
			cnt++;
		}
		sum += Q[i];
		ans += (sum + (long long) X * cnt) * C[i + 1];
	}
	cout << ans << "\n";
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int tt = 1;
	/* cin >> tt; */
	while(tt--) Main();
}