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 <fstream>
#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
using namespace std;

int main() {
  // ifstream cin("../test.txt");
  char a[20][20];
  for (int i = 0; i < 20; i++) {
    for (int j = 0; j < 20; j++) {
      a[i][j] = '0';
    }
  }
  char c;

  vector<string> shape(7);
  shape[0] = "1100110000000000";
  shape[1] = "1000100010001000";
  shape[2] = "1111000000000000";
  shape[3] = "1000100000000000";
  shape[4] = "1100011000000000";
  shape[5] = "1000110001000000";
  shape[6] = "1100100000000000";

  while (cin >> c) {
    a[0][0] = c;
    for (int i = 1; i < 8; i++) {
      cin >> c;
      a[0][i] = c;
    }
    for (int i = 1; i < 8; i++) {
      for (int j = 0; j < 8; j++) {
        cin >> c;
        a[i][j] = c;
      }
    }

    // for (int i = 0; i < 8; i++) {
    //   for (int j = 0; j < 8; j++) {
    //     cout << a[i][j];
    //   }
    //   cout << endl;
    // }


    int h,w;
    for (int i = 0; i < 64; i++) {
      if (a[i/8][i%8] == '1') {
        h = i / 8;
        w = i % 8;
        break;
      }
    }

    // cout << h << " " << w << endl;

    for (int s = 0; s < 7; s++) {
      bool flag = true;
      for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 4; j++) {
          if (shape[s][4 * i + j] != a[h + i][w + j])
            flag = false;
        }
      }

      if (flag) {
        cout << (char)('A' + s) << endl;
        break;
      }
    }

  }
}

C++: #include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <fstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

/*
A 2*2 B 1*4 C 4*1 D 01 E 110 F 10 G 011
                    11   011   11   110
                    10         01
*/

int main() {
	while (true) {
		string in[4];
		string tmp;
		int j=0;
		for (int i=0; i<8; i++) {
			cin >> tmp;
			if (tmp != "00000000") {
				in[j] = tmp;
				j++;
			}
		}
		if (j == 4) {
			cout << "B" << endl;
		} else if (j == 1) {
			cout << "C" << endl;
		} else if (j == 2) {
			if (in[0] == in[1]) {
				cout << "A" << endl;
			} else if (in[0] > in[1]) {
				cout << "E" << endl;
			} else {
				cout << "G" << endl;
			}
		} else {
			if (in[0] > in[1]) {
				cout << "F" << endl;
			} else {
				cout << "D" << endl;
			}
		}
		scanf("\n");
	}
	return 0;
}

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

int main() {
  char str[20][20];
  while(1) {
    for ( int i = 4; i < 12; i++ ){
      for ( int j = 4; j < 12; j++ ) {
      cin >> str[i][j];
      if ( cin.eof() ) return 0;
      }
    }
    char ans;
    for ( int i = 4; i < 12; i++ ) {
      for ( int j = 4; j < 12; j++ ) {
      if ( str[i][j] == '1' && str[i][j+1] == '1' && 
	   str[i+1][j] == '1' && str[i+1][j+1] == '1' ) ans = 'A';
      else if ( str[i][j] == '1' && str[i+1][j] == '1' &&
		str[i+2][j] == '1' && str[i+3][j] =='1' ) ans = 'B';
      else if ( str[i][j] == '1' && str[i][j+1] == '1' &&
		str[i][j+2] == '1' && str[i][j+3] == '1' ) ans = 'C';
      else if ( str[i][j] == '1' && str[i+1][j-1] == '1' &&
		str[i+1][j] == '1' && str[i+2][j-1] == '1' ) ans = 'D';
      else if ( str[i][j] == '1' && str[i][j+1] == '1' &&
		str[i+1][j+1] == '1' && str[i+1][j+2] == '1' ) ans = 'E';
      else if ( str[i][j] == '1' && str[i+1][j] == '1' &&
		str[i+1][j+1] == '1' && str[i+2][j+1] == '1' ) ans = 'F';
      else if ( str[i][j] == '1' && str[i][j+1] == '1' &&
		str[i+1][j-1] == '1' && str[i+1][j] == '1' ) ans = 'G';
							 
      }
    }
    cout << ans << endl;
  }
  return 0;
}

C++: #include "bits/stdc++.h"
#include<unordered_map>
#include<unordered_set>
#pragma warning(disable:4996)
using namespace std;
using ld = long double;
const ld eps = 1e-9;

//// < "d:\d_download\visual studio 2015\projects\programing_contest_c++\debug\a.txt" > "d:\d_download\visual studio 2015\projects\programing_contest_c++\debug\b.txt"

map<set<pair<int, int>>, int>mp;

int main() {
	mp[set<pair<int, int>>{make_pair(0, 0), make_pair(0, 1), make_pair(0, 2), make_pair(0, 3)}] = 1;
	mp[set<pair<int, int>>{make_pair(0, 0), make_pair(0, 1), make_pair(1, 1), make_pair(1, 0)}] = 0;
	mp[set<pair<int, int>>{make_pair(0, 0), make_pair(1, 0), make_pair(2, 0), make_pair(3, 0)}] = 2;
	mp[set<pair<int, int>>{make_pair(0, 1), make_pair(1, 0), make_pair(0, 2), make_pair(1, 1)}] = 3;
	mp[set<pair<int, int>>{make_pair(0, 0), make_pair(1, 0), make_pair(2,1), make_pair(1, 1)}] = 4;
	mp[set<pair<int, int>>{make_pair(0, 0), make_pair(0, 1), make_pair(1, 1), make_pair(1, 2)}] = 5;
	mp[set<pair<int, int>>{make_pair(1, 0), make_pair(0, 1), make_pair(1, 1), make_pair(2, 0)}] = 6;
	vector<string>sts(8);
	while (cin >> sts[0]) {
		for (int i = 1; i < 8; ++i)cin >> sts[i];
		int minx = 10;
		int miny = 10;
		
		for (int i = 0; i < 8; ++i) {
			for (int j = 0; j < 8; ++j) {
				if (sts[i][j] == '1') {
					minx = min(minx, j);
					miny = min(miny, i);
				}
			}
		}
		set<pair<int, int>>ps;
		for (int i = 0; i < 8; ++i) {
			for (int j = 0; j < 8; ++j) {
				if (sts[i][j] == '1') {
					ps.emplace(j - minx, i - miny);
				}
			}
		}
		if (mp.find(ps) == mp.end())assert(false);
		cout <<char( 'A' + mp[ps]) << endl;
	}
	return 0;
}