#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

template<typename T>
void print_vector(vector<T> v, char delimiter=' '){
    for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter;
    cout << v.back() << endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    ll n, m, x; cin >> n >> m >> x;
    vector<vector<ll>> q(m);
    for(int i = 0; i < n; i++) {
        int a, b; cin >> a >> b; b--;
        q[b].push_back(a);
    }
    priority_queue<ll> que;
    for(int i = 0; i < m; i++){
        if(q[i].empty()) continue;
        sort(q[i].begin(), q[i].end(), greater<ll>());
        q[i][0] += x;
        for(ll x: q[i]) {
            que.push(x);
        }
    }
    int k; cin >> k;
    vector<int> c(k);
    for(int i = 0; i < k; i++) cin >> c[i];
    sort(c.begin(), c.end());
    ll ans = 0;
    for(int i = 1; i <= n; i++){
        auto p = lower_bound(c.begin(), c.end(), i);
        int j = p-c.begin();
        ll y = que.top(); que.pop();
        // debug_value(k-j);
        ans += (k-j)*y;
    }
    cout << ans << endl;
}