#define	_USE_MATH_DEFINES
#include <iostream>
#include <algorithm>
#include <functional>
#include <vector>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cfloat>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <string>
#include <set>
using namespace std;
char s[100][100];
int main(){
	

	while(1){
		int x,y;
		bool f=false;
		for(int i=1;i<=8;i++){
			for(int j=1;j<=8;j++){
				cin>>s[i][j];
				if(s[i][j]=='1'&&!f){
					y=i;
					x=j;
					f=true;
				}
			}
		}
		
		if(s[y][x]=='1'&&s[y+1][x]=='1'&&s[y][x+1]=='1'&&s[y+1][x+1]=='1')
			cout<<"A"<<endl;
		else if(s[y][x]=='1'&&s[y+1][x]=='1'&&s[y+2][x]=='1'&&s[y+3][x]=='1')
			cout<<"B"<<endl;
		else if(s[y][x]=='1'&&s[y][x+1]=='1'&&s[y][x+2]=='1'&&s[y][x+3]=='1')
			cout<<"C"<<endl;
		else if(s[y][x]=='1'&&s[y+1][x]=='1'&&s[y+1][x-1]=='1'&&s[y+2][x-1]=='1')
			cout<<"D"<<endl;
		else if(s[y][x]=='1'&&s[y][x+1]=='1'&&s[y+1][x+1]=='1'&&s[y+1][x+2]=='1')
			cout<<"E"<<endl;
		else if(s[y][x]=='1'&&s[y+1][x]=='1'&&s[y+1][x+1]=='1'&&s[y+2][x+1]=='1')
			cout<<"F"<<endl;
		else if(s[y][x]=='1'&&s[y][x+1]=='1'&&s[y+1][x]=='1'&&s[y+1][x-1]=='1')
			cout<<"E"<<endl;
		
	}
}