fn main() {
	let mut s = String::new();
	std::io::stdin().read_line(&mut s).ok();
	let n: Vec<i16> = s.split_whitespace().flat_map(str::parse).collect();
	let (o, t) = (n[0] % 10, n[0] / 10 + n[1]);
	let a = match o + t - n[2] {
		x if o < x => o + 10 * (x - o),
		x if 0 < x => x,
		x if x.abs() <= 9 && t > 0 => x + 9,
		_ => 0,
	};
	if a > 0 {
		println!("{a}")
	} else {
		println!("Impossible")
	}
}