#include <iostream>
#include <string>
using namespace std;
void solve() {
	bool ok = false;
	for (int i = 1; i <= 3; ++i) {
		char ch;
		bool a = false, b = false, c = false, s = false;
		for (int j = 1; j <= 3; ++j) {
			cin >> ch;
			if (ch == 'a')
				a = true;
			else if (ch == 'b')
				b = true;
			else if (ch == 'c')
				c = true;
			else s = true;
		}
		if (!ok && s) {
			ok = true;
			if (a && c)
				cout << "B\n";
			if (a && b)
				cout << "C\n";
			if (b && c)
				cout << "A\n";
		}
	}
}
int main() {
	int t;
	cin >> t;
	while (t--)
		solve();
	return 0;
}