#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    ll N,M,X; cin >> N >> M >> X;
    vector<vector<ll>> col(M);
    rep(i,N) {
        ll A,B; cin >> A >> B; B--;
        col[B].push_back(A);
    }

    vector<ll> D;
    rep(i,M) if(!col[i].empty()) {
        sort(col[i].begin(), col[i].end());
        col[i].back() += X;
        for(ll x : col[i]) D.push_back(x);
    }
    sort(D.rbegin(), D.rend());

    vector<ll> sumD(N + 1, 0);
    rep(i,N) sumD[i + 1] += sumD[i] + D[i];
    ll ans = 0;
    int K; cin >> K;
    rep(i,K) {
        int c; cin >> c;
        ans += sumD[c];
    }
    cout << ans << endl;
}