use std::io::*;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let a: usize = itr.next().unwrap().parse().unwrap();
    let b: usize = itr.next().unwrap().parse().unwrap();
    let _: usize = itr.next().unwrap().parse().unwrap();
    let d: usize = itr.next().unwrap().parse().unwrap();
    if d >= 10 {
        println!("Impossible");
    } else {
        let mut ans = 0;
        let mut cnt = 0;
        let mut mul = 0;
        for _ in 0..b {
            ans += 50 * (1 << mul);
            cnt += 1;
            mul = cnt / 100;
        }
        for _ in 0..a {
            ans += 100 * (1 << mul);
            cnt += 1;
            mul = cnt / 100;
        }
        println!("Possible");
        println!("{}", ans);
    }
}