fn main() {
	let mut s = String::new();
	std::io::stdin().read_line(&mut s).ok();
	let n: Vec<i64> = s.split_whitespace().flat_map(str::parse).collect();
	let m = n[0] / ((12 + n[3]) * n[1]) * 12;
	let mut r = n[0] % ((12 + n[3]) * n[1]);
	let mut a = 0;
	while r > 0 {
		a += 1;
		r -= n[1];
		if n[2] <= a && a < n[2] + n[3] {
			r -= n[1];
		}
	}
	println!("{}", m + a);
}