use std::collections::BinaryHeap;


fn main() {
    let mut nabxy = String::new();
    std::io::stdin().read_line(&mut nabxy).ok();
    let nabxy: Vec<usize> = nabxy.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nabxy[0];
    let a = nabxy[1];
    let b = nabxy[2];
    let x = nabxy[3];
    let y = nabxy[4];
    let mut h = String::new();
    std::io::stdin().read_line(&mut h).ok();
    let h: Vec<usize> = h.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();

    let mut upper = 1usize << 60;
    let mut lower = 0usize;
    while upper > lower {
        let middle = (upper + lower) / 2;
        let h = h.iter().map(|&v| if v > middle { v - middle } else { 0 }).collect::<Vec<_>>();
        let mut pque = BinaryHeap::new();
        for &v in h.iter() { if v > 0 { pque.push(v); }}
        let mut cnt = 0usize;
        while cnt < a && !pque.is_empty() {
            cnt += 1;
            let val = pque.pop().unwrap();
            if val > x { pque.push(val - x); }
        }
        let summary = pque.iter().sum::<usize>();
        let flg = b * y >= summary;
        if !flg {
            lower = middle + 1;
        } else {
            upper = middle;
        }
    }
    println!("{}", upper);
}