#include <bits/stdc++.h>
using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int N,S,T,K; cin >> N >> S >> T >> K; S--,T--;
    vector<int> A(N);
    for(auto &a : A) cin >> a;
    int mina = min_element(A.begin(),A.end())-A.begin();
    if(A.at(S)+A.at(T) <= K) cout << 1 << endl;
    else if(A.at(S)+A.at(mina) <= K){
        if(A.at(mina)+A.at(T) <= K) cout << 2 << endl;
        else cout << -1 << endl;
    }
    else cout << -1 << endl;
    
}