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)
	}
}

C++: #include <algorithm>
#include <cmath>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <cassert>
#include <functional>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
//#define LOG(...)
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define RSORT(c) sort((c).rbegin(),(c).rend())
#define CLR(a) memset((a), 0 ,sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int dx[] = { -1, 0, 1, 0 }; const int dy[] = { 0, 1, 0, -1 };

int main() {
	bool cell[8][8] = {false};
	int ans = 0;
	REP(i, 8){
		string s;
		cin >> s;
		REP(j, 8){
			if (s[j] == '1')
				cell[i][j] = true;
		}
	}

	REP(i, 8){
		REP(j, 8){
			if (cell[i][j]){
				REP(k, 3)
					REP(l, 3)
					if (i + (k - 1) >= 0 && i + (k - 1) < 8 && j + (l - 1) >= 0 && j + (l - 1) < 8 && cell[i + (k - 1)][j + (l - 1)])
						ans += 1 << (8-(k * 3 + l));
				i = j =8;
			}
		}
	}
	switch (ans){
	case 27:
		cout << 'A' << endl;
		break;
	case 18:
		cout << 'B' << endl;
		break;
	case 24:
		cout << 'C' << endl;
		break;
	case 22:
		cout << 'D' << endl;
		break;
	case 25:
		cout << 'E' << endl;
		break;
	case 19:
		cout << 'F' << endl;
		break;
	case 30:
		cout << 'G' << endl;
		break;
	}

}

C++: #include<iostream>
#include<string>
#include<vector>
#include<cstdio>
#include<sstream>
#include<algorithm>
#include<cmath>
#include<map>
#include<functional>
#include<queue>
#include<stack>
#include<set>
using namespace std;
int stoi(string x){stringstream ss;ss<<x;int tmp;ss>>tmp;return tmp;}
string itos(int x){stringstream ss;ss<<x;return ss.str();}
char ta[12][12];
int main(){
while(cin>>ta[0][0]){
	int y,x;
	bool f=1;
	for(int i=0;i<8;i++){
		for(int j=(i==0);j<8;j++){
			char now;
			cin>>now;
			if(now=='1'&&f){y=i,x=j;f=0;}
			ta[i][j]=now;
		}
	}
	if(ta[y][x+1]=='1'&&ta[y+1][x]=='1'&&ta[y+1][x+1]=='1')cout<<"A";
	
	else if(ta[y+1][x]=='1'&&ta[y+2][x]=='1'&&ta[y+3][x]=='1')cout<<"B";
	
	else if(ta[y][x+1]=='1'&&ta[y][x+2]=='1'&&ta[y][x+3]=='1')cout<<"C";
	
	else if(ta[y][x+1]=='1'&&ta[y+1][x+1]=='1'&&ta[y+1][x+2]=='1')cout<<"E";
	
	else if(ta[y+1][x]=='1'&&ta[y+1][x+1]=='1'&&ta[y+2][x+1]=='1')cout<<"F";
	
	else if(ta[y][x+1]=='1'&&ta[y+1][x]=='1'&&ta[y+1][x-1]=='1')cout<<"G";
	
	else if(ta[y+2][x-1]=='1'&&ta[y+1][x]=='1'&&ta[y+1][x-1]=='1')cout<<"D";

	cout<<endl;
		for(int i=0;i<12;i++)for(int j=0;j<12;j++)ta[i][j]='0';
}
	
	return 0;
}

C++: #include <cstdio>
#define REP(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i,n) REP(i,0,n)
char m[16][16], buf[16];
int main()
{
	while (true) {
		bool done = false;
		rep(i, 8) if (scanf("%s", m[i]) == EOF) done = true;
		if (done) break;

		char res = 0;
		rep(i, 8) rep(j, 8) {
			if (m[i][j] == '1') {
				if (j < 5 && m[i][j+1]=='1'&&m[i][j+2]=='1'&&m[i][j+3]=='1') {
					res = 'C';
				}
				else if (j < 7 && i < 7 && m[i][j+1]=='1'&&m[i+1][j]=='1'&&m[i+1][j+1]=='1') {
					res = 'A';
				}
				else if (i < 5 && m[i+1][j]=='1'&&m[i+2][j]=='1'&&m[i+3][j]=='1') {
					res = 'B';
				}
				else if (i < 6 && j > 0 && m[i+1][j-1]=='1'&&m[i+1][j]=='1'&&m[i+2][j-1]=='1') {
					res = 'D';
				}
				else if (i < 7 && j < 6 && m[i][j+1]=='1'&&m[i+1][j+1]=='1'&&m[i+1][j+2]=='1') {
					res = 'E';
				}
				else if (i < 6 && j < 7 && m[i+1][j+1]=='1'&&m[i+1][j]=='1'&&m[i+2][j+1]=='1') {
					res = 'F';
				}
				else if (i < 7 && j < 7 && j > 0 && m[i][j+1]=='1'&&m[i][j+1]=='1'&&m[i-1][j-1]=='1') {
					res = 'G';
				}
			}
			if (res > 0) goto BREAK;
		}
BREAK:
		printf("%c\n", res);
	}
	return 0;
}

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

double eps = 1e-10;

int main() {
	string s[16];
	while(cin >> s[0]){
		for(int i = 1; i < 8; ++i){
			cin >> s[i];
		}
		int h, w;
		for(int i = 0; i < 8; ++i){
			for(int j = 0; j < 8; ++j){
				if(s[i][j] == '1'){
					h = i;
					w = j;
					goto next;
				}
			}
		}
		next:;
		if(s[h + 1][w] == '1' && s[h][w + 1] == '1' && s[h + 1][w + 1] == '1'){
			cout << "A" << endl;
		}
		else if(s[h + 1][w] == '1' && s[h + 2][w] == '1' && s[h + 3][w] == '1'){
			cout << "B" << endl;
		}
		else if(s[h][w + 1] == '1' && s[h][w + 2] == '1' && s[h][w + 3] == '1'){
			cout << "C" << endl;
		}
		else if(s[h + 1][w - 1] == '1' && s[h + 1][w] == '1' && s[h + 2][w - 1] == '1'){
			cout << "D" << endl;
		}
		else if(s[h][w + 1] == '1' && s[h + 1][w + 1] == '1' && s[h + 1][w + 2] == '1'){
			cout << "E" << endl;
		}
		else if(s[h + 1][w] == '1' && s[h + 1][w + 1] == '1' && s[h + 2][w + 1] == '1'){
			cout << "F" << endl;
		}
		else if(s[h][w + 1] == '1' && s[h + 1][h] == '1' && s[h + 1][w - 1] == '1'){
			cout << "G" << endl;
		}
	}
	return 0;
}