#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int N,M,X;
ll A[202020],B[202020];
vector<ll> P[202020];
void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>M>>X;
	FOR(i,N) {
		cin>>x>>y;
		P[y-1].push_back(x);
	}
	vector<ll> pat,S;
	FOR(i,M) if(P[i].size()) {
		sort(ALL(P[i]));
		P[i].back()+=X;
		FORR(p,P[i]) pat.push_back(p);
	}
	sort(ALL(pat));
	reverse(ALL(pat));
	S.push_back(0);
	FORR(p,pat) S.push_back(S.back()+p);
	ll sum=0;
	cin>>k;
	FOR(i,k) {
		cin>>x;
		sum+=S[x];
	}
	cout<<sum<<endl;
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}