#include <bits/stdc++.h>
    using namespace std;
    #include <math.h>
    #include <iomanip>
    #include <cstdint>
    #include <string>
    #include <sstream>
    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; }
    #define rep(i,n) for (int i = 0; i < (n); ++i)
    typedef long long ll;
    typedef long double ld;
    typedef unsigned long long ull;
    using P=pair<ll,ll>;
    const ll INF=1e18;
    const int mod=1e9+7;

    void solve(){
        ll n,m,x;
        cin>>n>>m>>x;
        vector<vector<int>>t(m);
        rep(i,n){
            int a,b;
            cin>>a>>b;b--;
            t[b].push_back(a);
        }
        int k;
        cin>>k;
        vector<int>c(k);
        rep(i,k)cin>>c[i];
        
        vector<ll>a;
        rep(i,m){sort(t[i].rbegin(),t[i].rend());}
        rep(i,m){
            if(t[i].empty()){continue;}
            a.push_back(t[i][0]+x);
            for(int j=1;j<t[i].size();j++){a.push_back(t[i][j]);}
        }
        sort(a.rbegin(),a.rend());
        vector<ll>sum(a.size()+1);
        rep(i,a.size()){sum[i+1]=sum[i]+a[i];}
        ll ans=0;
        rep(i,k){ans+=sum[c[i]];}
        cout<<ans<<endl;
    } 

    int main(){
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        
        solve();

        return 0;
    }