1 1 2 2
1000000000 1000000000
1
 1 1 1000000000 1000000000
100 1000000000
1
 1 1 10 18
5 6
5
 2 1 1000000000 2000000000
111 999999999
101 999999998
1
 4 13 400 600
13 30
1 19
1 160
1 113
58 73 15 319 194 362 128 157 336 162 77 90 96
 1 15 100 200
283 8
30 58 16 45 80 82 55 95 24 23 86 28 51 47 20
 3 2 300 400
24 68
13 65
15 113
127 177
 1 1 2 1
1 10
1
 4 2 7 15
10 9
4 4
9 3
4 10
1 6
 2 1 1000000000 2000000000
111 1000000000
101 1000000000
5
 2 1 1000000000 2000000000
111 999999998
101 999999998
1
 1 1 1000000000 1000000000
1 1000000000
1

1000000000
 -1
 5
 111
 1
 -1
 -1
 -1
 4
 101
 -1
 -1

#include <bits/stdc++.h>
using namespace std;
int n, g, len, t;
int arr[200200];
int car[200200][2];
int main() {
  cin.sync_with_stdio(false);
  cin >> n >> g >> len >> t;
  for (int i = 0; i < n; i++) {
    cin >> car[i][0] >> car[i][1];
  }
  for (int i = 0; i < g; i++) {
    cin >> arr[i];
  }
  arr[g++] = 0;
  arr[g++] = len;
  sort(arr, arr + g);
  long long l = 0, r = 1ll << 40;
  while (r - l > 1) {
    long long mid = (r + l) / 2;
    long long ti = 0;
    bool ok = true;
    for (int i = 1; i < g; i++) {
      long long dist = arr[i] - arr[i - 1];
      long long cap = min(0ll + mid, 2 * dist);
      if (dist > mid) {
        ok = false;
        break;
      }
      long long sp = mid - dist;
      ti += sp + 2 * (dist - sp);
    }
    if (!ok) {
      l = mid;
      continue;
    }
    if (ti > t) {
      l = mid;
    } else {
      r = mid;
    }
  }
  long long sol = 1ll << 40;
  for (int i = 0; i < n; i++) {
    if (car[i][1] >= r) {
      sol = min(sol, car[i][0] + 0ll);
    }
  }
  cout << sol << endl;
}
