fn main() {
	let mut s = String::new();
	std::io::stdin().read_line(&mut s).ok();
	let mut n: Vec<i64> = s.split_whitespace().flat_map(str::parse).collect();
	if n[3] > 9 {
		println!("Impossible");
		return;
	}
	println!("Possible");
	let mut r = 1;
	let mut a = 0;
	for i in 0..n[0] + n[1] {
		if i < n[1] {
			a += r
		} else {
			a += 2 * r
		}
		if i % 100 == 99 {
			r *= 2;
		}
	}
	println!("{}", a * 50);
}