#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
const int C = 26;
void add(int &x, int y) {
  x += y;
  while (x >= MOD) x -= MOD;
  while (x < 0) x += MOD;
}
int fix(int x) {
  while (x >= MOD) x -= MOD;
  while (x < 0) x += MOD;
  return x;
}
int pw(int a, int b) {
  int ret = 1;
  while (b) {
    if (b & 1) ret = 1ll * ret * a % MOD;
    b >>= 1;
    a = 1ll * a * a % MOD;
  }
  return ret;
}
const int MAXN = 5e5 + 10;
int n, m, k, s;
int r[MAXN], c[MAXN], safes[MAXN];
vector<pair<int, long long>> vec[MAXN];
int mn[MAXN], mx[MAXN], cnt[MAXN];
long long ans;
void process(int row, int col, long long cost) {
  int pos = lower_bound(safes, safes + s, col) - safes;
  if (pos < s)
    vec[row + 1].push_back({safes[pos], cost + safes[pos] - col + 1});
  if (pos - 1 >= 0) {
    pos--;
    vec[row + 1].push_back({safes[pos], cost + col - safes[pos] + 1});
  }
}
void solve() {
  memset(mn, 63, sizeof(mn));
  memset(mx, -1, sizeof(mx));
  cin >> n >> m >> k >> s;
  k++;
  for (int i = 0; i < k; i++) {
    if (i < k - 1)
      cin >> r[i] >> c[i];
    else
      r[i] = c[i] = 1;
    r[i]--, c[i]--, mn[r[i]] = min(mn[r[i]], c[i]),
                    mx[r[i]] = max(mx[r[i]], c[i]), cnt[r[i]]++;
  }
  for (int i = 0; i < s; i++) cin >> safes[i], safes[i]--;
  sort(safes, safes + s);
  int rem = k;
  vec[0].push_back({0, 0});
  ans = 1e18;
  long long xx = 0;
  for (int i = 0; rem && i < n; i++) {
    bool fl = rem == cnt[i];
    rem -= cnt[i];
    if (mx[i] >= 0) {
      vector<pair<int, long long>> vecTemp;
      sort(vec[i].begin(), vec[i].end());
      for (int l = 0; l < (int)vec[i].size();) {
        int r = l;
        while (r < (int)vec[i].size() && vec[i][l].first == vec[i][r].first)
          r++;
        vecTemp.push_back(vec[i][l]);
        l = r;
      }
      vec[i] = vecTemp;
      for (auto x : vec[i]) {
        int col = x.first;
        long long cost = x.second + xx;
        if (mx[i] >= 0) {
          {
            long long temp = cost;
            if (mn[i] < col) temp += col - mn[i];
            temp += mx[i] - min(col, mn[i]);
            if (fl) ans = min(ans, temp);
            process(i, mx[i], temp);
          }
          {
            long long temp = cost;
            if (mx[i] > col) temp += mx[i] - col;
            temp += max(col, mx[i]) - mn[i];
            if (fl) ans = min(ans, temp);
            process(i, mn[i], temp);
          }
        }
      }
      xx = 0;
    } else
      vec[i + 1] = vec[i], xx++;
  }
  cout << ans << "\n";
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int te = 1;
  for (int w = 1; w <= te; w++) {
    solve();
  }
  return 0;
}
