use proconio::{input, marker::Usize1};
fn main() {
    input! {
        n: usize,
        s: Usize1,
        t: Usize1,
        k: usize,
        a: [usize; n],
    }
    let amin = a.iter().min().unwrap();
    let mut res = 0;
    if a[s] + a[t] <= k {
        res = 1;
    } else if a[s] + amin <= k && a[t] + amin <= k {
        res = 2;
    } else {
        res = -1;
    }
    println!("{res}");
}