#include <bits/stdc++.h>

using namespace std;

const int MAXN = 505;
const int ALPHA = 26;

char s[MAXN], t[MAXN];


int isFirstWinner() {
	int n = strlen(s);
	vector<int> cntA(ALPHA), cntB(ALPHA);
	for (int i = 0; i < n; i++) {
		cntA[s[i] - 'a']++;
		cntB[t[i] - 'a']++;
	}
	// If there exists a character in s with frequency >= 2, but doesn't exist in t.
	for (int i = 0; i < ALPHA; i++) {
		if (cntA[i] >= 2 && cntB[i] == 0) {
			return true;
		}
	}
	int subset = true;
	int hasUniqueCharacter = false;
	for (int i = 0; i < ALPHA; i++) {
		if (cntB[i] > 0 && cntA[i] == 0) {
			subset = false;
		}
		if (cntA[i] > 0 && cntB[i] == 0) {
			hasUniqueCharacter = true;
		}
	}
	// If each character of t also occurs in s, and there exists a unique character in s that doesn't occur in t.
	return subset && hasUniqueCharacter;
}

int main() {
	int T;
	scanf("%d", &T);
	while (T--) {
		scanf("%s %s", s, t);
		puts(isFirstWinner() ? "A" : "B");
	}
	return 0;
}