#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
const int M = 5e5 + 3;
const int INF = 1e9;
set<int> safe;
long long dist(vector<long long> pts) {
  long long ret = 0;
  for (int i = 0; i + 1 < pts.size(); i++) ret += abs(pts[i] - pts[i + 1]);
  return ret;
}
long long calc(long long p, long long l, long long r) {
  auto it = safe.lower_bound(p);
  long long ret = 2e9;
  int sc;
  if (it != safe.end()) {
    sc = *it;
    ret = min(ret, dist({p, sc, l, r}));
  }
  if (it != safe.begin()) {
    it--;
    sc = *it;
    ret = min(ret, dist({p, sc, l, r}));
  }
  return ret;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n, m, k, q;
  cin >> n >> m >> k >> q;
  vector<int> L(n + 1, INF), R(n + 1, 0);
  for (int i = 1; i <= k; i++) {
    int r, c;
    cin >> r >> c;
    L[r] = min(L[r], c);
    R[r] = max(R[r], c);
  }
  while (q--) {
    int b;
    cin >> b;
    safe.insert(b);
  }
  long long pL, pR, ansL, ansR;
  if (R[1]) {
    pL = L[1], pR = R[1];
    ansL = dist({1, R[1], L[1]});
    ansR = dist({1, L[1], R[1]});
  } else {
    pL = pR = 1;
    ansL = ansR = 0;
  }
  long long ans = min(ansL, ansR);
  long long last_row = 1;
  for (int i = 2; i <= n; i++) {
    if (!R[i]) continue;
    long long newR =
        min(calc(pL, L[i], R[i]) + ansL, calc(pR, L[i], R[i]) + ansR);
    long long newL =
        min(calc(pL, R[i], L[i]) + ansL, calc(pR, R[i], L[i]) + ansR);
    pL = L[i], pR = R[i];
    ansL = newL, ansR = newR;
    ans = min(ansL, ansR);
    last_row = i;
  }
  ans += last_row - 1;
  cout << ans << "\n";
}
