E0055.cpp

// Problem Code: ABGAME

#include <iostream>
#include <string>
#include <vector>
#include <numeric>
#include <functional>

using namespace std;

char winner(string S) {
	int a, b, count, XOR;
	vector<int> nims;
	a = b = 0;
	for(int j, i=0 ; i<S.length() ; i++)
		if(S[i] != '.') {
			count = 0;
			for(j = i+1 ; j < S.length() && S[j] == '.' ; j++)
				count++;
			if(j != S.length() && S[i] != S[j])
				nims.push_back(count);
			else {
				if(S[i] == 'A')
					a += count;
				else
					b += count;
			}
			i = j;
		}
	if(a != b)
		return (a > b) ? 'A' : 'B';
	XOR = accumulate(nims.begin(), nims.end(), 0, bit_xor<int>());
	return (XOR) ? 'A' : 'B';
}

int main() {
	int T;
	string s;
	cin >> T;
	while(T--) {
		cin >> s;
		cout << winner(s) << endl;
	}
	return 0;
}