#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

    ll N, M, X, A, B, K, ans=0;
    cin >> N >> M >> X;
    vector<priority_queue<ll>> v(M+1);
    priority_queue<ll> que;
    for (int i=0; i<N; i++){
        cin >> A >> B;
        v[B].push(A);
    }

    for (int i=1; i<=M; i++){
        bool f=1;
        while(!v[i].empty()){
            A = v[i].top();
            v[i].pop();
            if (f){
                A += X;
                f=0;
            }
            que.push(A);
        }
    }
    vector<ll> S(N+1);
    for (int i=1; i<=N; i++){
        A = que.top();
        que.pop();
        S[i] += S[i-1] + A;
    }
    cin >> K;
    for (int i=0; i<K; i++){
        cin >> A;
        ans += S[A];
    }

    cout << ans << endl;

    return 0;
}