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

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

MwpBQkMKQz9CCkJDQQpCQ0EKQ0E/CkFCQwo/QUIKQkNBCkFCQwo=

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