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
}

func main() {
	for {
		var board [][]int
		var ans string
		if board = scanBoard(); reflect.DeepEqual(board, [][]int{}) {
			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)
	}
}

C++: #include <cstdio>
using namespace std;

int main(){
	char ch[8][8];
	bool judged;
	
	while((scanf("%s", ch[0])) != EOF){
		for(int i = 1; i < 8; i++){
				scanf("%s", ch[i]);
		}
		
		judged = false;
		for(int i = 0; i < 8; i++){
			for(int j = 0; j < 8; j++){
				if(ch[i][j] == '1'){
					//A
					if(i + 1 < 8 && ch[i + 1][j] == '1' &&
					 j + 1 < 8 && ch[i][j + 1] == '1' &&
					 ch[i + 1][j + 1] == '1'){
						printf("A\n");
						judged = true;
						break;
					}
					//B
					if(i + 3 < 8 && ch[i + 1][j] == '1' &&
					 ch[i + 2][j] == '1' && ch[i + 3][j] == '1'){
						printf("B\n");
						judged = true;
						break;
					}
					//C
					if(j + 3 < 8 && ch[i][j + 1] == '1' &&
					 ch[i][j + 2] == '1' && ch[i][j + 3] == '1'){
						printf("C\n");
						judged = true;
						break;
					}
					//D
					if(i + 2 < 8 && j - 1 >= 0 &&
					 ch[i + 1][j - 1] == '1' && ch[i + 1][j] == '1' &&
					 ch[i + 2][j - 1] == '1'){
						printf("D\n");
						judged = true;
						break;
					}
					//E
					if(i + 1 < 8 && j + 2 < 8 &&
					 ch[i][j + 1] == '1' && ch[i + 1][j + 1] == '1' &&
					 ch[i + 1][j + 2] == '1'){
						printf("E\n");
						judged = true;
						break;
					}
					//F
					if(i + 1 < 8 && j + 2 < 8 &&
					 ch[i][j + 1] == '1' && ch[i + 1][j + 1] == '1' &&
					 ch[i + 1][j + 2] == '1'){
						printf("F\n");
						judged = true;
						break;
					}
					//G
					if(i + 1 < 8 && j + 1 < 8 && j - 1 >= 0 &&
					 ch[i + 1][j] == '1' && ch[i][j + 1] == '1' &&
					 ch[i + 1][j - 1] == '1'){
						printf("G\n");
						judged = true;
						break;
					}
				}
			}
			
			if(judged) break;
		}
	}
	
	return 0;
}

C++: //33
#include<iostream>
#include<algorithm>

using namespace std;

int main(){
  for(;;){
    char g[8][8];
    for(int y=0;y<8;y++){
      for(int x=0;x<8;x++){
	if(!(cin>>g[y][x]))return 0;
      }
    }
    for(int y=0;y<8;y++){
      for(int x=0;x<8;x++){
	if(g[y][x]=='1'){
	  int a=0;
	  for(int i=0;i<4;i++){
	    for(int j=0;j<4;j++){
	      a=(a<<1)+(g[y+i][x+j]=='1');
	    }
	  }
	  static const int f[]={0xcc00,0x8888,0xf000,0x4c80,0xc600,0x8c40,0x6c00};
	  cout<<char(find(f,f+7,a)-f+'A')<<endl;
	  goto next;
	}
      }
    }
  next:
    ;
  }
  return 0;
}

C++: #include<iostream>
#include<string>
using namespace  std;

string table[8];
bool range(int y,int x)
{
	if (y < 0 || x < 0 || y >= 8 || x >= 8)return false;
	return true;
}
bool A(int y, int x)
{
	int dx[] = {0,1,1,0};
	int dy[] = {0,0,1,1};
	for (int i = 0; i < 4; i++)
	{
		int ny = y + dy[i];
		int nx = x + dx[i];
		if (range(ny, nx) && table[ny][nx] == '1')continue;
		return false;
	}
	return true;
}
bool B(int y, int x)
{
	int dx[] = { 0, 0, 0, 0 };
	int dy[] = { 0, 1, 2, 3 };
	for (int i = 0; i < 4; i++)
	{
		int ny = y + dy[i];
		int nx = x + dx[i];
		if (range(ny, nx) && table[ny][nx] == '1')continue;
		return false;
	}
	return true;
}
bool C(int y, int x)
{
	int dx[] = { 0, 1, 2, 3 };
	int dy[] = { 0, 0, 0, 0 };
	for (int i = 0; i < 4; i++)
	{
		int ny = y + dy[i];
		int nx = x + dx[i];
		if (range(ny, nx) && table[ny][nx] == '1')continue;
		return false;
	}
	return true;
}
bool D(int y, int x)
{
	int dx[] = { 0, 0, -1, -1 };
	int dy[] = { 0, 1,1, 2 };
	for (int i = 0; i < 4; i++)
	{
		int ny = y + dy[i];
		int nx = x + dx[i];
		if (range(ny, nx) && table[ny][nx] == '1')continue;
		return false;
	}
	return true;
}
bool E(int y, int x)
{
	int dx[] = { 0, 1, 1, 2 };
	int dy[] = { 0, 0, 1, 1 };
	for (int i = 0; i < 4; i++)
	{
		int ny = y + dy[i];
		int nx = x + dx[i];
		if (range(ny, nx) && table[ny][nx] == '1')continue;
		return false;
	}
	return true;
}
bool F(int y, int x)
{
	int dx[] = { 0, 0, 1, 1 };
	int dy[] = { 0, 1, 1, 2 };
	for (int i = 0; i < 4; i++)
	{
		int ny = y + dy[i];
		int nx = x + dx[i];
		if (range(ny, nx) && table[ny][nx] == '1')continue;
		return false;
	}
	return true;
}
bool G(int y, int x)
{
	int dx[] = { 0, 1, 0, -1 };
	int dy[] = { 0, 0, 1, 1 };
	for (int i = 0; i < 4; i++)
	{
		int ny = y + dy[i];
		int nx = x + dx[i];
		if (range(ny, nx) && table[ny][nx] == '1')continue;
		return false;
	}
	return true;
}
char check(int y, int x)
{
	if (A(y, x))return 'A';
	else if (B(y, x))return 'B';
	else if (C(y, x))return 'C';
	else if (D(y, x))return 'D';
	else if (E(y, x))return 'E';
	else if (F(y, x))return 'F';
	else if (G(y, x)) return 'G';
	else return 0;
}
int main()
{
	while (true)
	{
		for (int i = 0; i < 8; i++)
		{
			if (!(cin >> table[i]))return 0;
		}
		bool find = false;
		for (int i = 0; i < 8; i++)
		{
			for (int j = 0; j < 8; j++)
			{
				int ret = check(i,j);
				if (ret > 0)
				{
					find = true;
					cout << ((char)ret) << endl;
					break;
				}
			}
			if (find)break;
		}
	}
	return 0;
}

C++: #include<iostream>
#include<string>
using namespace std;

string b[11];
int solve(int i, int j){
    if(b[i][j+1]=='1'&&b[i+1][j]=='1'&&b[i+1][j+1]=='1') cout << 'A';
    else if(b[i+1][j]=='1'&&b[i+2][j]=='1'&&b[i+3][j]=='1') cout << 'B';
    else if(b[i][j+1]=='1'&&b[i][j+2]=='1'&&b[i][j+3]=='1') cout << 'C';
    else if(b[i][j+1]=='1'&&b[i+1][j+1]=='1'&&b[i+1][j+2]=='1') cout << 'E';
    else if(b[i+1][j]=='1'&&b[i+1][j+1]=='1'&&b[i+2][j+1]=='1') cout << 'F';
    else if(b[i+1][j-1]=='1'&&b[i+1][j]=='1'&&b[i+2][j-1]=='1') cout << 'D';
    else cout << 'G';
}
    
int main(){
    int i, j;
    char c;
    while(cin >> b[0]){
        b[0] += "000";
        for(int i=1;i<8;i++){
            cin >> b[i];
            b[i] += "000";
        }
        for(int i=8;i<11;i++){
            b[i] = "00000000000";
        }
        for(int i=0;i<64;i++){
            if(b[i/8][i%8] == '1'){
                solve(i/8, i%8);
                cout << endl;
                break;
            }
        }
    }
}