#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] = {0, 0, 0};
		for(int i=0; i<3; i++){
			for(int j=0; j<3; j++){
				if(grid[i][j] != '?'){
					int ind = grid[i][j] - 'A';
					f[ind]++;
				}
			}
		}
		char ch = 0;
		for(int i=0; i<3; i++){
			if(f[i] < 3){
				ch = f[i] + 97;
			}
		}
		cout << ch << endl;
		/*if(f[0] == 2)cout << "A" << endl;
		else if(f[1] == 2)cout << "B" <<endl;
		else if(f[2] == 2)cout << "C" <<endl;*/
	}
	return 0;
}

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

MwpBQkMKQz9CCkJDQQpCQ0EKQ0E/CkFCQwo/QUIKQkNBCkFCQwo=

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