//0036
#include<iostream>
using namespace std;

struct ca {
	int x;
	int y;
};

int main() {
	ca l[4];
	int a = 0;
	for (int i = 0; i < 8; i++){
		for (int j = 0; j < 8; j++){
			char c;
			cin >> c;
			if (c == '1')
			{
				l[a].x = i;
				l[a].y = j;
				a++;
			}
		}
	}
	int x = l[0].x;
	int y = l[0].y;
	if (l[1].x == x&&l[1].y == y + 1){
		//[l0][l1]
		//ACEG
		if (l[3].x == x + 1 && l[3].y == y + 1)
			cout << 'A';
		else if (l[3].y == y + 3)
			cout << 'C';
		else if (l[3].x == x + 1 && l[3].y == y + 2)
			cout << 'E';
		else cout << 'G';
	}
	else if (l[1].x == x + 1 && l[1].y == y){
		/*[l0]
		  [l1]*/
		//BF
		if (l[3].x == x + 3 && l[3].y == y) 
			cout << 'B';
		else cout << 'F';
	}
	else cout << 'D';
	cout << endl;
	char c;
	cin >> c;
	return 0;
}