#include <bits/stdc++.h>
#define rep(i, l, r) for (int i = (l); i < (r); i++)
using namespace std;

typedef long long ll;

int main() {
    int N, M, X, K;
    cin >> N >> M >> X;
    vector<int> A(N), B(N);
    rep(i, 0, N) cin >> A[i] >> B[i];
    cin >> K;
    vector<int> C(K);
    rep(i, 0, K) cin >> C[i];
    vector<vector<int>> D(M);
    rep(i, 0, N) D[B[i] - 1].push_back(A[i]);
    rep(i, 0, M) sort(D[i].begin(), D[i].end());
    rep(i, 0, M) if (D[i].size() > 0) D[i].back() += X;
    vector<ll> E(0), S(N + 1, 0);
    rep(i, 0, M) {
        rep(j, 0, D[i].size()) {
            E.push_back(D[i][j]);
        }
    }
    sort(E.begin(), E.end());
    rep(i, 0, N) S[i + 1] = S[i] + E[N - 1 - i];
    ll ans = 0;
    rep(i, 0, K) ans += S[C[i]];
    cout << ans << endl;
}