#include <iostream>
using namespace std;
 
int main() {
	int t;
	cin >> t;
	while(t--){
		char grid[3][3];
		for(int i=0; i<3; i++){
			for(int j=0; j<3; j++){
				cin >> grid[i][j];
			}
		}
		int f[3];
		for(int i=0; i<3; i++) f[i] = 0;
		for(int i=0; i<3; i++){
			for(int j=0; j<3; j++){
				if(grid[i][j] == '?'){
					for(int k=0; k<3; k++){
						int ind = grid[i][k] - 'A';
						f[ind]++;
					}
				}
				else
					continue;
			}
		}
		char ch;
		for(int i=0; i<3; i++){
			if(f[i] == 2){
				ch = i + 65;
				break;
			}
		}
 
		cout << ch << endl;
	}
	return 0;
}

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

MwpBQkMKQz9CCkJDQQpCQ0EKQ0E/CkFCQwo/QUIKQkNBCkFCQwo=

3
ABC
C?B
BCA
BCA
CA?
ABC
?AB
BCA
ABC