#include <bits/stdc++.h>
using namespace std;
const long long maxn = 2e5 + 9;
vector<long long> vec[maxn];
long long safe[maxn], vis[maxn];
vector<long long> row;
bool cmp(long long a, long long b) { return a > b; }
long long dp[maxn][2];
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int i, j, k, n, m, q;
  cin >> n >> m >> k >> q;
  for (i = 0; i < k; i++) {
    long long x, y;
    cin >> x >> y;
    vec[x].push_back(y);
    if (!vis[x]) {
      row.push_back(x);
      vis[x] = 1;
    }
  }
  if (!vis[1]) {
    row.push_back(1);
    vec[1].push_back(1);
  }
  for (i = 0; i < q; i++) cin >> safe[i];
  sort(safe, safe + q);
  sort(row.begin(), row.end(), cmp);
  for (i = 0; i < row.size(); i++) {
    long long x = row[i];
    sort(vec[x].begin(), vec[x].end());
  }
  dp[0][0] = vec[row[0]][vec[row[0]].size() - 1] - vec[row[0]][0];
  dp[0][1] = dp[0][0];
  for (i = 1; i < row.size(); i++) {
    long long r = row[i], lst_r = row[i - 1], len = vec[r].size(),
              lst_len = vec[lst_r].size();
    long long lst_y1 = vec[lst_r][0], lst_y2 = vec[lst_r][lst_len - 1];
    long long y1 = vec[r][0], y2 = vec[r][len - 1];
    long long pos1 = lower_bound(safe, safe + q, lst_y1) - safe;
    long long pos3 = lower_bound(safe, safe + q, lst_y2) - safe;
    long long dis1 = 0x3f3f3f3f3f3f3f3f, dis2 = 0x3f3f3f3f3f3f3f3f,
              dis3 = 0x3f3f3f3f3f3f3f3f, dis4 = 0x3f3f3f3f3f3f3f3f,
              dis5 = 0x3f3f3f3f3f3f3f3f, dis6 = 0x3f3f3f3f3f3f3f3f,
              dis7 = 0x3f3f3f3f3f3f3f3f, dis8 = 0x3f3f3f3f3f3f3f3f;
    if (pos1 != q) {
      dis1 = abs(safe[pos1] - lst_y1) + abs(y2 - safe[pos1]) + abs(y2 - y1) +
             abs(r - lst_r);
      dis5 = abs(lst_y1 - safe[pos1]) + abs(y1 - safe[pos1]) + abs(y2 - y1) +
             abs(r - lst_r);
    }
    if (pos1 > 0) {
      long long pos2 = pos1 - 1;
      dis2 = abs(lst_y1 - safe[pos2]) + abs(y2 - safe[pos2]) + abs(y2 - y1) +
             abs(r - lst_r);
      dis6 = abs(lst_y1 - safe[pos2]) + abs(y1 - safe[pos2]) + abs(y2 - y1) +
             abs(r - lst_r);
    }
    if (pos3 != q) {
      dis3 = abs(safe[pos3] - lst_y2) + abs(y2 - safe[pos3]) + abs(y2 - y1) +
             abs(r - lst_r);
      dis7 = abs(lst_y2 - safe[pos3]) + abs(y1 - safe[pos3]) + abs(y2 - y1) +
             abs(r - lst_r);
    }
    if (pos3 > 0) {
      long long pos4 = pos3 - 1;
      dis4 = abs(lst_y2 - safe[pos4]) + abs(y2 - safe[pos4]) + abs(y2 - y1) +
             abs(r - lst_r);
      dis8 = abs(lst_y2 - safe[pos4]) + abs(y1 - safe[pos4]) + abs(y2 - y1) +
             abs(r - lst_r);
    }
    dp[i][0] =
        min(dp[i - 1][0] + min(dis1, dis2), dp[i - 1][1] + min(dis3, dis4));
    dp[i][1] =
        min(dp[i - 1][0] + min(dis5, dis6), dp[i - 1][1] + min(dis7, dis8));
  }
  long long rs = row.size();
  long long ans = dp[rs - 1][0] + vec[1][0] - 1;
  cout << ans << endl;
}
