#include <bits/stdc++.h>

[[nodiscard]] int_fast32_t solve([[maybe_unused]] const uint_fast32_t N, const uint_fast32_t S, const uint_fast32_t T, const uint_fast32_t K, const std::vector<uint_least32_t>& A) noexcept
{
	if (A[S - 1] + A[T - 1] <= K) return 1;
	else if (std::max(A[S - 1], A[T - 1]) + *std::min_element(A.begin(), A.end()) <= K) return 2;
	else return -1;
}

int main()
{
	std::cin.tie(nullptr);
	std::ios::sync_with_stdio(false);
	
	uint_fast32_t N, S, T, K;
	std::cin >> N >> S >> T >> K;
	std::vector<uint_least32_t> A(N);
	for (auto& a : A) std::cin >> a;

	std::cout << solve(N, S, T, K, A) << '\n';
	return 0;
}