func fx() -> String{
    let n = readLine()!.split(separator: " ").map{Int($0)!}
    let (A,B,C) = (n[0],n[1],n[2])
    for a in 0...C{
        if a>A+9{break}
        let z = A + B * 10 - a - (C - a) * 10
        if z >= 0{return String(z)}
    }
    return "Impossible"
}

print(fx())