let n = readLine()!.split(separator: " ").map{Int($0)!}
var (A,B,C,D) = (n[0],n[1],n[2],n[3])

if D < 10{
    print("Possible")
var c = 0
var m = 1
var t = 0
while A + B > 0{
    if B > 0{
        B -= 1
        t += 50 * m
    }else{
        A -= 1
        t += 100 * m
    }
    c += 1
    if c % 100 == 0{
        m *= 2
    }
}
print(t)
}else{
    print("Impossible")
}