import java.util.Scanner; import java.math.BigInteger; public class Main { public static void main(String[] args) { Scanner cin=new Scanner(System.in); int T; T=cin.nextInt(); BigInteger a,b; for(int cas=1;cas<=T;cas++){ a=cin.nextBigInteger(2); b=cin.nextBigInteger(2); a=a.gcd(b); System.out.println("Case #"+cas+": "+a.toString(2)); } } }