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;
const int mod = 1e9 + 7;
const int inf = INT_MAX;
template <typename type>
inline type sqr(type value) {
  return (value * value);
}
struct mas {
  long long cost, V;
};
long long n, k, second, mid, ans_local, ans_all, t, pos[5000001];
mas car[5000001];
bool comp(mas a, mas b) {
  if (a.V < b.V)
    return 1;
  else if (a.V == b.V && a.cost > b.cost)
    return 1;
  else
    return 0;
}
bool chek(long long x) {
  long long v = car[x].V;
  long long timer = 0;
  if (v < pos[1]) return 0;
  if (pos[1] * 2 <= v)
    timer = pos[1];
  else
    timer = pos[1] * 3 - v;
  for (int i = 2; i <= k; i++) {
    if (pos[i] - pos[i - 1] > v)
      return 0;
    else {
      if ((pos[i] - pos[i - 1]) * 2 <= v) timer += pos[i] - pos[i - 1];
      timer += (pos[i] - pos[i - 1]) * 3 - v;
    }
  }
  if (second - pos[k] > v) return 0;
  if ((second - pos[k]) * 2 <= v)
    timer += second - pos[k];
  else
    timer += (second - pos[k]) * 3 - v;
  return (timer <= t);
}
int main() {
  ans_all = 1e14;
  cin >> n >> k >> second >> t;
  for (int i = 1; i <= n; i++) {
    cin >> car[i].cost >> car[i].V;
  }
  sort(car + 1, car + n + 1, comp);
  for (int i = 1; i <= k; i++) {
    cin >> pos[i];
  }
  sort(pos + 1, pos + k + 1);
  if (!chek(n)) {
    cout << -1;
    return 0;
  }
  int l = 1;
  int r = n;
  while (l + 1 < r) {
    mid = (l + r) >> 1;
    if (chek(mid))
      r = mid;
    else
      l = mid;
  }
  if (chek(l))
    ans_local = l;
  else
    ans_local = r;
  for (int i = ans_local; i <= n; i++) {
    ans_all = min(ans_all, car[i].cost);
  }
  cout << ans_all;
}
