#nullable enable

#region
var _input = Array.Empty<string>();
var _iter = 0;
string String()
{
    while (_iter >= _input.Length) (_input, _iter) = (Console.ReadLine()!.Split(' '), 0);
    return _input[_iter++];
}
T I<T>() where T : IParsable<T> => T.Parse(String(), null);
#endregion

T[] Range<T>(int n, Func<T> F) => Enumerable.Range(0, n).Select(_ => F()).ToArray();

var n = I<int>();
var s = I<int>() - 1;
var t = I<int>() - 1;
var k = I<int>();
var az = Range(n, I<int>);

var ans = -1;
if (az[s] + az[t] <= k) ans = 1;
else if (az.Min() + Math.Max(az[s], az[t]) <= k) ans = 2;
Console.WriteLine(ans);