#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#include <utility>
#include <functional>
#include <time.h>
#include <stack>
#include <array>
#include <list>
#include <atcoder/all>
#define popcount __builtin_popcount
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef pair<int, int> P;
using mint=modint998244353;

int main()
{
    int n, m; ll x;
    cin>>n>>m>>x;
    vector<vector<int>> v(m);
    for(int i=0; i<n; i++){
        int a, b;cin>>a>>b;
        b--;
        v[b].push_back(a);
    }
    vector<int> w;
    for(int i=0; i<m; i++){
        if(v[i].empty()) continue;
        sort(v[i].begin(), v[i].end(), greater<int>());
        v[i][0]+=x;
        for(auto a:v[i]){
            w.push_back(a);
        }
    }
    sort(w.begin(), w.end(), greater<int>());
    vector<ll> ws(n+1);
    for(int i=0; i<n; i++) ws[i+1]=ws[i]+w[i];
    ll ans=0;
    int k; cin>>k;
    for(int i=0; i<k; i++){
        int c; cin>>c;
        ans+=ws[c];
    }
    cout<<ans<<endl;
    return 0;
}