#include <bits/stdc++.h>
using namespace std;
using ll = int64_t;
#define rep(i, s, e) for (int i = s; i < e; ++i)
#define sort_(a) stable_sort(a.begin(), a.end())
#define rsort(a) stable_sort(a.rbegin(), a.rend())
#define join(a, d) accumulate(a.begin() + 1, a.end(), a[0], [](string s, string t) { return s + d + t; })
#define sum(a) reduce(begin(a), end(a), remove_reference<decltype(*begin(a))>::type{})
#define min_(a) reduce(begin(a) + 1, end(a), a[0], [](int x, int y) { return min(x, y); })
constexpr double degrees(double a) { return a * 180.0 / M_PI; }
constexpr double radians(double a) { return (a * M_PI) / 180.0; }
constexpr long mod = 1e9 + 7;

int main(int, [[maybe_unused]] char *argv[]) {
#ifdef DEBUG
  freopen(argv[1], "r", stdin);
#endif

  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(15);

  int N, S, T, K;
  cin >> N >> S >> T >> K;
  vector<int> A(N);
  rep(i, 0, N) cin >> A[i];

  if (A[S - 1] + A[T - 1] <= K) {
    cout << "1\n";
  } else if (A[S - 1] + min_(A) <= K) {
    cout << "2\n";
  } else {
    cout << "-1\n";
  }
  return 0;
}