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 N = 2e5 + 7;
const int M = 2000;
const long long mod = 1e9 + 7;
int n, k, s, t;
pair<int, int> val[N];
int g[N];
bool check(int fuel) {
  int timecheck = 0;
  for (int i = 1; i <= k + 1; i++) {
    if (fuel >= (g[i] - g[i - 1]) * 2) {
      timecheck += (g[i] - g[i - 1]);
    } else if (fuel >= (g[i] - g[i - 1])) {
      int dif = (g[i] - g[i - 1]);
      timecheck += (fuel - dif) + (dif * 2 - fuel) * 2;
    } else {
      return false;
    }
  }
  if (timecheck > t) {
    return false;
  } else {
    return true;
  }
}
int main() {
  scanf("%d%d%d%d", &n, &k, &s, &t);
  for (int i = 1; i <= n; i++) {
    scanf("%d%d", &val[i].second, &val[i].first);
  }
  sort(val + 1, val + n + 1);
  int l = 0, r = n + 1;
  val[n + 1].first = 1e9;
  val[n + 1].second = 1e9;
  for (int i = 1; i <= k; i++) {
    scanf("%d", &g[i]);
  }
  g[0] = 0;
  g[k + 1] = s;
  sort(g + 1, g + k + 1);
  while (r - l > 1) {
    int mid = (l + r) / 2;
    if (check(val[mid].first)) {
      r = mid;
    } else {
      l = mid;
    }
  }
  int ans = INT_MAX;
  for (int i = r; i <= n; i++) {
    ans = min(ans, val[i].second);
  }
  printf("%d\n", ans);
}
