Go: package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"reflect"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func scanBoard() [][]int {
	ret := make([][]int, 8)
	for k := range ret {
		ret[k] = make([]int, 8)
		for l := range ret[k] {
			ret[k][l] = 0
		}
	}
	for i := 0; i < 8; i++ {
		scanner.Scan()
		row := strings.Split(scanner.Text(), "")
		if reflect.DeepEqual(row, []string{}) {
			break
		}
		for j := 0; j < 8; j++ {
			ret[i][j], _ = strconv.Atoi(row[j])
		}
	}
	return ret
}

var emptyBoard = [][]int{{0,0,0,0,0,0,0,0},
						 {0,0,0,0,0,0,0,0},
						 {0,0,0,0,0,0,0,0},
	                     {0,0,0,0,0,0,0,0},
	                     {0,0,0,0,0,0,0,0},
	                     {0,0,0,0,0,0,0,0},
	                     {0,0,0,0,0,0,0,0},
	                     {0,0,0,0,0,0,0,0}}

func main() {
	for {
		var board [][]int
		var ans string
		if board = scanBoard(); reflect.DeepEqual(board, emptyBoard) {
			break
		}
		// fmt.Println(board)
		for i := 0; i < 7; i++ {
			for j := 0; j < 7; j++ {
				if board[i][j] == 1 && board[i+1][j] == 1 && board[i][j+1] == 1 && board[i+1][j+1] == 1 {
					ans = "A"
				}
			}
		}
		for i := 0; i < 5; i++ {
			for j := 0; j < 8; j++ {
				if board[i][j] == 1 && board[i+1][j] == 1 && board[i+2][j] == 1 && board[i+3][j] == 1 {
					ans = "B"
				}
			}
		}
		for i := 0; i < 8; i++ {
			for j := 0; j < 5; j++ {
				if board[i][j] == 1 && board[i][j+1] == 1 && board[i][j+2] == 1 && board[i][j+3] == 1 {
					ans = "C"
				}
			}
		}
		for i := 0; i < 6; i++ {
			for j := 0; j < 7; j++ {
				if board[i][j+1] == 1 && board[i+1][j] == 1 && board[i+1][j+1] == 1 && board[i+2][j] == 1 {
					ans = "D"
				}
			}
		}
		for i := 0; i < 7; i++ {
			for j := 0; j < 6; j++ {
				if board[i][j] == 1 && board[i][j+1] == 1 && board[i+1][j+1] == 1 && board[i+1][j+2] == 1 {
					ans = "E"
				}
			}
		}
		for i := 0; i < 7; i++ {
			for j := 0; j < 6; j++ {
				if board[i][j+1] == 1 && board[i][j+2] == 1 && board[i+1][j] == 1 && board[i+1][j+1] == 1 {
					ans = "G"
				}
			}
		}
		for i := 0; i < 6; i++ {
			for j := 0; j < 7; j++ {
				if board[i][j] == 1 && board[i+1][j] == 1 && board[i+1][j+1] == 1 && board[i+2][j+1] == 1 {
					ans = "F"
				}
			}
		}
		fmt.Println(ans)
		fmt.Scanln()
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int(i) = 0;(i)<(n);(i)++)
#define pb push_back
#define mp make_pair
#define All(X) X.begin(),X.end()

int main(){
	vector<int> vx, vy;
	while (1){
		vx.clear();
		vy.clear();
		REP(i, 8){
			string str;
			cin >> str;
			if (cin.eof()){
				return 0;
			}	
			REP(j, 8){
				if (str[j] == '1'){
					vx.pb(i);
					vy.pb(j);
				}
			}
		}
		char ans = 'G';
		if (vx[0] == vx[1] && vy[0] == vy[2]) ans = 'A';
		if (vy[0] == vy[1] && vy[0] == vy[2] && vy[0] == vy[3]) ans = 'B';
		if (vx[0] == vx[1] && vx[0] == vx[2] && vx[0] == vx[3]) ans = 'C';
		if (vx[1] == vx[2] && vy[1] == vy[3] && vy[0] == vy[2]) ans = 'D';
		if (vx[0] == vx[1] && vx[2] == vx[3] && vy[1] == vy[2] && vy[0] + 2 == vy[3]) ans = 'E';
		if (vx[1] == vx[2] && vy[0] == vy[1] && vy[2] == vy[3]) ans = 'F';
		
		cout << ans << endl;
		
	}
}

C++:  
 #include<iostream>
 #include<stdio.h>
 #include<string>
 #include<math.h>
 #include<iomanip>
 #include<algorithm>
 #include<string.h>
 #include<cctype>
 #include<map>
 #include<set>
 #include<vector>
 #include<sstream>
 #include<stack>
 #include<queue>
 
 using namespace std;

 char arr[8][8];
 
 int main()
 {
   while(cin>>arr[0][0])
   {
     int x[4],y[4];
     int cnt1,cnt2;
     cnt1=cnt2=0;
     if(arr[0][0]=='1') 
     {
       x[cnt1++]=0;
       y[cnt2++]=0;                   
     }
     for(int i=0;i<8;i++)
     {
       for(int j=0;j<8;j++)
       {
           if(i==0&&j==0) continue;
           else
           {
             cin>>arr[i][j];
             if(arr[i][j]=='1')
             {
               x[cnt1++]=j;
               y[cnt2++]=i;                
             }
           }    
                 
       }        
     }             
     if(y[0]==y[1]&&y[2]==y[3]&&x[1]==x[0]+1&&x[3]==x[2]+1) cout<<"A"<<endl;
     else if(x[0]==x[1]&&x[1]==x[2]&&x[2]==x[3]) cout<<"B"<<endl;
     else if(y[0]==y[1]&&y[1]==y[2]&&y[2]==y[3]) cout<<"C"<<endl;
     else if(y[1]==y[2]&&y[3]==y[0]+2) cout<<"D"<<endl;
     else if(x[1]==x[2]&&(x[3]==x[0]+2)) cout<<"E"<<endl;
     else if(y[1]==y[2]&&y[3]==y[0]+2) cout<<"F"<<endl;
     else cout<<"G"<<endl;        
   }
   //while(1);
   return 0;
 }

C++: #include <iostream>

using namespace std;

/** Problem0036 : A Figure on Surface **/
int main()
{
	char board[8][9];
	
	while (1) {
		for (int i=0; i<8; i++)
			cin.getline(board[i], 9, '\n');
		if (cin.eof()) break;
		
		for (int y=0; y<8; y++) {
			for (int x=0; x<8; x++) {
				if (board[y][x] == '1') {
					if (board[x+1][y] == '1' && board[x][y+1] == '1' && board[x+1][y+1] == '1')
						cout << "A" << endl;
					else if (board[y+1][x] == '1' && board[y+2][x] == '1' && board[y+3][x] == '1')
						cout << "B" << endl;
					else if (board[y][x+1] == '1' && board[y][x+2] == '1' && board[y][x+3] == '1')
						cout << "C" << endl;
					else if (board[y+1][x] == '1' && board[y+1][x-1] == '1' && board[y+2][x-1] == '1')
						cout << "D" << endl;
					else if (board[y][x+1] == '1' && board[y+1][x+1] == '1' && board[y+1][x+2] == '1')
						cout << "E" << endl;
					else if (board[y+1][x] == '1' && board[y+1][x+1] == '1' && board[y+2][x+1] == '1')
						cout << "F" << endl;
					else
						cout << "G" << endl;
					goto endloop;
				}
			}
		}
	endloop:
		;
	}
	
	return 0;
}

C++: #include<iostream>
using namespace std;
int main() {
    while (cin){
        char c[10][10];
        for (int i = 0; i < 8; i++)
            for (int j = 0; j < 8; j++)
                cin >> c[i][j];
        int a, b;
        for (int i = 0; i < 8; i++) {
            for (int j = 0; j < 8; j++) {
                if (c[i][j] == '1') {
                    a = i;
                    b = j;
                    goto C;
                }
            }
        }
    C:
        if (c[a][b + 1] == '1') {
            if (c[a + 1][b] == '1') {
                if (c[a + 1][b + 1] == '1')
                    cout << 'A';
                else cout << 'G';
            }
            else {
                if (c[a + 1][b + 1] == '1')
                    cout << 'E';
                else cout << 'C';
            }
        }
        else if (c[a + 1][b + 1] == '1')
            cout << 'F';
        else if (c[a + 1][b - 1] == '1')
            cout << 'D';
        else cout << 'B';
        cout << endl;
    }
    return 0;
}