use std::io::{Read,stdin};

fn main() {
    let mut buf = String::new();
    stdin().read_to_string(&mut buf).unwrap();
    let mut tok = buf.split_whitespace();
    let mut get = || tok.next().unwrap();
    macro_rules! get {
        ($t:ty) => (get().parse::<$t>().unwrap());
        () => (get!(i64));
    }
    
    let a = get!();
    let b = get!();
    let _c = get!();
    let d = get!();
    
    if d >= 10 {
        println!("Impossible");
        return;
    }
    
    println!("Possible");
    let mut ans = 0;
    let mut m = 1;
    for i in 0..a+b {
        if i > 0 && i % 100 == 0 {
            m *= 2;
        }
        if i < b {
            ans += 50 * m;
        } else {
            ans += 100 * m;
        }
    }
    
    println!("{}", ans);
    
}