#include <algorithm>
#include <iostream>
#include <queue>
using namespace std;
typedef long long ll;
typedef pair<ll, int> P;

int main()
{
    int n, m;
    ll x;
    cin >> n >> m >> x;
    P p[200005];
    for(int i = 0; i < n; i++){
        int a, b;
        cin >> a >> b;
        p[i] = P(a, b);
    }
    sort(p, p + n, greater<P>());
    int k;
    cin >> k;
    int d[200005]{0};
    for(int i = 0; i < k; i++){
        int c;
        cin >> c;
        d[c]++;
    }
    int j = 0;
    int c = k;
    ll ans = 0;
    queue<ll> que;
    bool b[200005]{0};
    for(int i = 0; i < n; i++){
        if(!b[p[i].second]){
            b[p[i].second] = true;
            while(!que.empty() && que.front() >= p[i].first + x){
                c -= d[j++];
                ans += que.front() * c;
                que.pop();
            }
            c -= d[j++];
            ans += (p[i].first + x) * c;
        }
        else que.push(p[i].first);
    }
    while(!que.empty()){
        c -= d[j++];
        ans += que.front() * c;
        que.pop();
    }
    cout << ans << endl;
}