#include<bits/stdc++.h>
#include<iostream>
using namespace std;
using LL = long long;
using P = pair<int,int>;
using Graph = vector<vector<int>>;
const int INF = 1 << 29;
const long long LINF = 1LL << 60;
#define all(x) (x).begin(), (x).end()
#define rep(i,n) for(int i = 0; i < (n); ++i)
template<class T>void chmin(T&a, T b){if(a > b) a = b;}
template<class T>void chmax(T&a, T b){if(a < b) a = b;}


int main(){
	int N, M, X; cin >> N >> M >> X;
	vector<vector<int>> problem(M,vector<int>());
	//ジャンル別に問題を整理
	for(int i = 0; i < N; ++i){
		int A, B; cin >> A >> B;
		--B;
		problem[B].push_back(A);
	}
	//その問題を降順に整理
	for(int i = 0; i < M; ++i){
		sort(problem[i].rbegin(), problem[i].rend());
	}
	//優先度の高い各ジャンルの一番高い得点に＋X
	for(int i = 0; i < M; ++i) problem[i][0] += X;
	vector<int> ALL;
	for(int i = 0; i < M; ++i){
		for(auto v : problem[i]){
			ALL.push_back(v);
		}
	}
	sort(ALL.rbegin(), ALL.rend());
	vector<int> S(N+1, 0);
	for(int i = 0; i < N; ++i) S[i+1] = S[i] + ALL[i];
	int K; cin >> K;
	int res = 0;
	for(int i = 0; i < K; ++i){
		int C; cin >> C;
		res += S[C];
	}
	cout << res << endl;
}