func main()
	var n: int :: cui@inputInt()
	var s: int :: cui@inputInt()
	var t: int :: cui@inputInt()
	var k: int :: cui@inputInt()
	var a: []int :: #[n]int
	for i(0, n - 1)
		do a[i] :: cui@inputInt()
	end for
	
	var as: int :: a[s - 1]
	var at: int :: a[t - 1]
	
	
	var ans: int :: 0
	if(as + at <= k)
		do ans :: 1
	else
		do a.sort()
		if(as + a[0] <= k & at + a[0] <= k)
			do ans :: 2
		else
			do ans :: -1
		end if
	end if
	do cui@print("\{ans}\n")
end func