#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
using mint = modint1000000007;
#endif
using ll = long long;
using ld = long double;
const ll INF = 1ll<<60;
const ld EPS = 1.0/1e9;
#define endl "\n"
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
#define del(x) sort(all(x)); x.erase(unique(all(x)),x.end());


int main(){
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  ll n,m,x; cin >> n >> m >> x;
  vector<priority_queue<ll>>que(m);
  rep(i,0,n){
    ll a,b; cin >> a >> b; b--;
    que[b].push(a);
  }
  queue<pair<ll,ll>>use;
  priority_queue<tuple<ll,ll,ll>>w;
  rep(i,0,m){
    if(!que[i].empty()){
      w.push({que[i].top()+x,i,1});
      que[i].pop();
    }
  }
  rep(i,0,m){
    while(!que[i].empty()){
      w.push({que[i].top(),i,0});
      que[i].pop();
    }
  }
  while(!w.empty()){
    ll p,q,r; tie(p,q,r)=w.top();
    if(r) p-=x; 
    use.push({p,q});
    w.pop();
  }
  vector<ll>sum(n+1);
  vector<ll>ind(n+1);
  set<ll>st;
  rep(i,0,n){
    sum[i+1]+=sum[i];
    sum[i+1]+=use.front().first;
    st.insert(use.front().second);
    ind[i+1]=st.size();
    use.pop();
  }
  ll ans=0;
  ll k; cin >> k;
  rep(i,0,k){
    ll p=0;
    ll c; cin >> c;
    p+=sum[c];
    p+=ind[c]*x;
    ans+=p;
  }
  cout << ans << endl;
}