import java.util.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		int n=scanner.nextInt();
		int l,i,j,k,w;

		for( l=0;l<n;l++){

		    boolean moreThanOnce=false;
		    boolean different=false;
			String s1=scanner.nextLine();
			String s2=scanner.nextLine();
			String s3=scanner.nextLine();




			for(i=0;i<s2.length();i++){
				if(!(s1.contains(String.valueOf(s2.charAt(i))))){different=true;}
			}

			for(j=0;j<s3.length();j++){
				if(s2.contains(String.valueOf(s3.charAt(j)))){moreThanOnce=true;}
				if(!(s1.contains(String.valueOf(s3.charAt(j))))){different=true;}
			}


			if(moreThanOnce || different){System.out.println("CHEATER");}


			// GETTING THE REST OF THE DISHES :
			if(!different && !moreThanOnce){


			for(k=0;k<s2.length();k++){
				s1=s1.replace(""+s2.charAt(k), "");

			}

			for(w=0;w<s3.length();w++){
				s1=s1.replace(""+s3.charAt(w), "");
				}


			char[] s=s1.replace(" ", "").toCharArray();
			Arrays.sort(s);
			//System.out.println("LOOP :"+l);
			System.out.println(s);} // end of second condition !
		} // end of main for
		scanner.close();
	}

}