package con_level_1half;
import java.util.Scanner;
public class Con825 {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		int a = s.nextInt() , b = s.nextInt() , c = s.nextInt();
		s.close();

		if(c >= a + b){
			System.out.println("Impossible");
		}else{
			int d = a + b - c;
			if(d < 10){
				if(d <= a){
					System.out.println(d);
				}else{
					System.out.println(a + (d - a) * 10);
				}
			}else{
				if(a > d){
					System.out.println((d + 1) % 10);
				}else{
					if(a > 10){
						System.out.println(a % 10 + (d - a + 1) * 10);
					}else{
						System.out.println(a + (d - a) * 10);
					}
				}
			}
		}
	}

}