public String solution(int n, int[] arr1, int[] arr2){

StringBuilder answer = new StringBuilder();

for(int i=0;i<n;i++){

if(arr1[i] == arr2[i])

answer.append("D");

else if ((arr1[i] ==1 && arr2[i] == 3) ||(arr1[i] ==2 && arr2[i] == 1) || (arr1[i] ==3 && arr2[i] == 2))

answer.append("A");

else

answer.append("B");

}

return answer.toString();

}

public static void main(String[] args) {

RockPaperScissors t = new RockPaperScissors();

Scanner scanner = new Scanner(System.in);

int n = scanner.nextInt();

int[] arr1 = new int[n];

int[] arr2 = new int[n];

for(int i=0; i< n ;i++){

arr1[i] = scanner.nextInt();

}

for(int i=0; i< n ;i++){

arr2[i] = scanner.nextInt();

}

for (char c : t.solution(n, arr1, arr2).toCharArray()) {

System.out.println(c);

}

}