import java.io.IOException; import java.util.NoSuchElementException; public class Main{ public static void main(String[] args){ FastScanner sc = new FastScanner(); int A = sc.nextInt(); int B = sc.nextInt(); int C = sc.nextInt(); int D = sc.nextInt(); if(D==10){ System.out.println("Impossible"); }else{ System.out.println("Possible"); int combo = 0; int ans = 0; for(int i=0;i