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(), "")
		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 < 8; i++ {
			for j := 0; j < 8; 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 < 8; 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 < 8; 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 < 8; i++ {
			for j := 0; j < 8; 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 < 8; i++ {
			for j := 0; j < 8; 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 < 8; i++ {
			for j := 0; j < 8; 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 < 8; i++ {
			for j := 0; j < 8; 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 <iostream>
#include <stdio.h>
using namespace std;

int main(){
	int mass[8][8];
	
	BEGIN:
	while(scanf("%d%d%d%d%d%d%d%d",(*mass[0]),(*mass[0])+1,(*mass[0])+2,(*mass[0])+3,(*mass[0])+4,
		(*mass[0])+5,(*mass[0])+6,(*mass[0])+7)!=EOF)
	{
		for(int i=1;i<8;i++){
			scanf("%d%d%d%d%d%d%d%d",(*mass[i]),(*mass[i])+1,(*mass[i])+2,(*mass[i])+3,(*mass[i])+4,
				(*mass[i])+5,(*mass[i])+6,(*mass[i])+7);
		}
		for(int i=0;i<8;i++){
			for(int j=0;j<8;j++){
				if(mass[i][j]){
					if(j==7){
						if(mass[i+1][j]){
							cout<<(mass[i+1][j-1]?"D\n":"B\n");
						}
					}else if(j==0){
						if(mass[i][j+1]){
							if(mass[i+1][j]) cout<<"A\n";
							else if(mass[i][j+2]) cout<<"C\n";
							else cout<<"E\n";
						}
						else cout<<(mass[i+1][j+1]?"F\n":"B\n");
					}else{
						if(mass[i][j+2]) cout<<"C\n";
						else if(mass[i][j+1]){
							if(mass[i+1][j]){
								cout<<(mass[i+1][j+1]?"A\n":"G\n");
							}
							else cout<<"E\n";
						}
						else if(mass[i+2][j]) cout<<"B\n";
						else cout<<(mass[i+1][j+1]?"F\n":"D\n");
					}
					goto BEGIN;
				}
			}
		}
	}
	return 0;
}

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

const double EPS = 1.0e-6;

int main()
{
	while(1){
		string all[8];
		bool endflg = false;
		for(int i=0; i<8; i++){
			if(!(cin>>all[i])) endflg = true;
			if(endflg) break;
		}
		if(endflg) break;

		string ans = "NG";
		for(int i=0; i<7; i++){
			bool breakflg = false;
			for(int j=0; j<7; j++){
				// ¡É©é
				if(all[i][j]-'0'==1&&all[i][j+1]-'0'==1){
					if(all[i+1][j]-'0'==1&&all[i+1][j+1]-'0'==1){
						ans = "A";
					} else if(all[i+1][j]-'0'==0&&all[i+1][j+1]-'0'==0){
						ans = "C";
					} else if(all[i+1][j]-'0'==1&&all[i+1][j+1]-'0'==0){
						ans = "G";
					} else if(all[i+1][j]-'0'==0&&all[i+1][j+1]-'0'==1){
						ans = "E";
					}
					breakflg = true;
					break;
				}
				// cÉ©é
				if(all[i][j]-'0'==1&&all[i+1][j]-'0'==1){
					if(all[i][j+1]-'0'==1&&all[i+1][j+1]-'0'==1){
						ans = "A";
					} else if(all[i][j+1]-'0'==0&&all[i+1][j+1]-'0'==0){
						ans = "B";
					} else if(all[i][j+1]-'0'==1&&all[i+1][j+1]-'0'==0){
						ans = "D";
					} else if(all[i][j+1]-'0'==0&&all[i+1][j+1]-'0'==1){
						ans = "F";
					}
					breakflg = true;
					break;
				}
			}
			if(breakflg) break;
		}
		if(ans == "NG"){
			// ·û`
			for(int i=0; i<7; i++){
				if(all[7][i]-'0'==1){
					ans = "C";
					break;
				}
				if(all[i][7]-'0'==1){
					ans = "B";
					break;
				}
			}
		}
		cout<<ans<<endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

typedef complex<int> P;

namespace std{
	bool operator < (const P &a,const P &b){
		if( a.real() != b.real() ) return a.real() < b.real();
		return a.imag() < b.imag();
	}
	bool operator == (const P &a,const P &b){
		if( a.real() != b.real() ) return false;
		return a.imag() == b.imag();
	}
};

vector<vector<P>> ptn = {
	{P(0,0),P(1,1),P(1,0),P(0,1)},
	{P(0,0),P(0,2),P(0,1),p(0,3)},
	{P(0,0),P(1,0),P(2,0),P(3,0)},
	{P(1,0),P(1,1),P(0,1),P(0,2)},
	{P(0,0),P(1,0),P(1,1),P(2,1)},
	{P(0,0),P(0,1),P(1,1),P(1,2)},
	{P(1,0),P(2,0),P(0,1),P(1,1)}
};

string s[8];
int main(){
	while(true){
		for(int i = 0 ; i < 8 ; i++){
			if(!(cin >> s[i]))exit(0);
			
		}
		for(int i = 0 ; i < 7 ; i++)
			sort(ptn[i].begin(),ptn[i].end());
		for(int i = -10 ; i <= 10 ; i++)
			for(int j = -10 ; j <= 10 ; j++){
				vector<P> tmp;
				for(int y = 0 ; y < 8 ; y++)
					for(int x = 0 ; x < 8 ; x++){
						if( s[y][x] == '1'){
							tmp.push_back(P(x-j,y-i));
						}
					}
				sort(tmp.begin(),tmp.end());
				for(int k = 0 ; k < 7 ; k++){
					if( tmp == ptn[k] ){
						cout << (char)(k+'A') << endl;
					}
				}
			}
	}
					
					
	
	
}

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

int main() {
	char c[8][8];
	while (cin >> c[0]) {
		for (int i = 1;i < 8;i++)cin >> c[i];

		int ax, ay;
		for (int i = 0;i < 8;i++) {
			for (int j = 0;j < 8;j++) {
				if (c[i][j] == '1') {
					ax = i;
					ay = j;
					goto floop;
				}
			}
		}
	floop:
		if (c[ax][ay] == c[ax][ay + 1]) {
			if (c[ax][ay] == c[ax + 1][ay] && c[ax + 1][ay] == c[ax + 1][ay])cout << 'A' << endl;
			else if (c[ax][ay] == c[ax][ay + 2] && c[ax][ay ] == c[ax][ay + 3])cout << 'C' << endl;
			else if (c[ax][ay] == c[ax + 1][ay + 1] && c[ax][ay] == c[ax + 1][ay + 2])cout << 'E' << endl;
			else cout << 'G' << endl;
		}
		if (c[ax][ay] == c[ax + 1][ay]) {
			if (ax<5&&c[ax][ay] == c[ax + 2][ay] && c[ax][ay] == c[ax + 3][ay])cout << 'B' << endl;
			else if (c[ax][ay] == c[ax + 1][ay + 1] && c[ax][ay] == c[ax + 2][ay + 1])cout << 'F' << endl;
			else if(c[ax+1][ay+1]=='0')cout << 'D' << endl;
		}
	}
	return 0;
}

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

const double EPS = 1.0e-6;

int main()
{
	while(1){
		string all[8];
		bool endflg = false;
		for(int i=0; i<8; i++){
			if(!(cin>>all[i])) endflg = true;
			if(endflg) break;
		}
		if(endflg) break;

		string ans;
		for(int i=0; i<7; i++){
			bool breakflg = false;
			for(int j=0; j<7; j++){
				// ツ可。ツづ可個ゥツづゥ
				if(all[i][j]-'0'==1&&all[i][j+1]-'0'==1){
					if(all[i+1][j]-'0'==1&&all[i+1][j+1]-'0'==1){
						ans = "A";
					} else if(all[i+1][j]-'0'==0&&all[i+1][j+1]-'0'==0){
						ans = "C";
					} else if(all[i+1][j]-'0'==1&&all[i+1][j+1]-'0'==0){
						ans = "G";
					} else if(all[i+1][j]-'0'==0&&all[i+1][j+1]-'0'==1){
						ans = "E";
					}
					breakflg = true;
					break;
				}
				// ツ縦ツづ可個ゥツづゥ
				if(all[i][j]-'0'==1&&all[i+1][j]-'0'==1){
					if(all[i][j+1]-'0'==1&&all[i+1][j+1]-'0'==1){
						ans = "A";
					} else if(all[i][j+1]-'0'==0&&all[i+1][j+1]-'0'==0){
						ans = "B";
					} else if(all[i][j+1]-'0'==1&&all[i+1][j+1]-'0'==0){
						ans = "D";
					} else if(all[i][j+1]-'0'==0&&all[i+1][j+1]-'0'==1){
						ans = "F";
					}
					breakflg = true;
					break;
				}
			}
			if(breakflg) break;
		}
		cout<<ans<<endl;
	}
	return 0;
}