#include <bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("O3")
#pragma GCC optimize("O2")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
  for (long long i = 0; i < v.size(); ++i) os << v[i] << " ";
  return os;
}
template <typename T>
ostream& operator<<(ostream& os, const set<T>& v) {
  for (auto it : v) os << it << " ";
  return os;
}
template <typename T, typename S>
ostream& operator<<(ostream& os, const pair<T, S>& v) {
  os << v.first << " " << v.second;
  return os;
}
const long long mod = 1e9 + 7;
const long long inf = 2e18;
const long long ninf = -2e18;
long long pow(long long a, long long b, long long m) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = (ans * a) % m;
    b /= 2;
    a = (a * a) % m;
  }
  return ans;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  time_t t1, t2;
  t1 = clock();
  long long n, m, ta, tb, k;
  cin >> n >> m >> ta >> tb >> k;
  vector<long long> arra(n);
  for (long long i = 0; i < n; i++) {
    cin >> arra[i];
  }
  vector<long long> arrb(m);
  for (long long i = 0; i < m; i++) {
    cin >> arrb[i];
  }
  if (n <= k || m <= k) {
    cout << -1 << '\n';
    return 0;
  }
  long long ans = -1;
  for (long long i = 0; i <= k; i++) {
    long long curr = arra[i] + ta;
    long long req = lower_bound(arrb.begin(), arrb.end(), curr) - arrb.begin();
    long long rem = k - i;
    if (req + rem > m - 1) {
      ans = inf;
      break;
    }
    long long ap = arrb[req + rem] + tb;
    ans = max(ap, ans);
  }
  if (ans != inf) {
    cout << ans << '\n';
  } else
    cout << -1 << '\n';
  t2 = clock();
  cerr << '\n' << t2 - t1 << '\n';
  return 0;
}
