use std::io::Read;

fn solve(abcd: Vec<u16>) {
    let limit = std::cmp::min(abcd[0], abcd[1] / abcd[2]);
    println!("{}", std::cmp::min(limit, abcd[3] / (1 + abcd[2])));
}

fn main() {
    let mut abcd = String::new();
    std::io::stdin().read_to_string(&mut abcd).ok();
    let abcd: Vec<u16> = abcd.trim().split('\n').next().unwrap().trim().split_whitespace().map(|s| s.parse::<u16>().unwrap()).collect();
    solve(abcd);
}