import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		sc.close();

		if (b == 0) {
			if (a <= c) {
				System.out.println("Impossible");
				return;
			}
		} else {
			if (a + b + 8 < c) {
				System.out.println("Impossible");
				return;
			}
		}

		if (b >= c && a != 0) {
			System.out.println(10 * (b - c) + a);
		} else {
			if (a + b > c) {
				while (a >= 10 && a + b - c >= 10) {
					a -= 10;
					b++;
				}
				System.out.println(a + b - c);
			} else {
				a += 9;
				b--;
				System.out.println(a + b - c + 1);
			}
		}
	}
}