let hantei a b = if (a + b) mod 3 = 0 then "Possible"
else if a mod 3 = 0 then "Possible"
else if b mod 3 = 0 then "Possible"
else "Impossible"
                 
let main () = 
Scanf.bscanf(read_line() "%d %d" (fun a b -> print_string(hantei a b)));;
                 
let () = main ()