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 < 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)
	}
}

Python: # -*- coding: utf-8 -*-
figures = {
    'A': [['1', '1'], ['1', '1']],
    'B': [['1'], ['1'], ['1'], ['1']],
    'C': [['1', '1', '1', '1']],
    'D': [['0', '1'], ['1', '1'], ['1', '0']],
    'E': [['1', '1', '0'], ['0', '1', '1']],
    'F': [['1', '0'], ['1', '1'], ['0', '1']],
    'G': [['0', '1', '1'], ['1', '1', '0']],
}


def iter_input_lines():
    try:
        while True:
            yield [list(input()) for _ in range(8)]
    except EOFError:
        return StopIteration


def f1():
    for lines in iter_input_lines():
        f2(lines)


def f2(lines):
    for n, figure in figures.items():
        found = f3(lines, figure)
        if found:
            print(n)


def f3(lines, figure):
    height = len(figure)
    width = len(figure[0])
    for h in range(0, 8, height):
        for w in range(0, 8, width):
            found = f4(lines, figure, height, width, h, w)
            if found:
                return True
        
        
def f4(lines, figure, height, width, h, w):
    _figure = [[lines[h+_h][w+_w] for _w in range(width)] 
               for _h in range(height)]
    if figure == _figure:
        return True

Python: def trim(N):
    num=[]
    for x in range(8):
        for y in range(8):
            if N[y][x]=="1":
                if not num:
                    refer=(x,y)
                num.append((x,y))
    num=[(x-refer[0],y-refer[1]) for x,y in num]
    return num
def points(point):
    if point==[(0,0),(0,1),(1,0),(1,1)]:print("A")
    if point==[(0,0),(0,1),(0,2),(0,3)]:print("B")
    if point==[(0,0),(1,0),(2,0),(3,0)]:print("C")
    if point==[(0,0),(0,1),(1,-1),(1,0)]:print("D")
    if point==[(0,0),(1,0),(1,1),(2,1)]:print("E")
    if point==[(0,0),(0,1),(1,1),(1,2)]:print("F")
    if point==[(0,0),(1,-1),(1,0),(2,-1)]:print("G")
while True:
    try:
        N=[input() for _ in range(8)]
        points(trim(N))
    except:break

Python: def trim(N):
    num=[]
    for x in range(8):
        for y in range(8):
            if N[y][x]=="1":
                if not num:
                    refer=(x,y)
                num.append((x,y))
    num=[(x-refer[0],y-refer[1]) for x,y in num]
    return num
def points(point):
    if point==[(0,0),(0,1),(1,0),(1,1)]:print("A")
    if point==[(0,0),(0,1),(0,2),(0,3)]:print("B")
    if point==[(0,0),(1,0),(2,0),(3,0)]:print("C")
    if point==[(0,0),(0,1),(1,-1),(1,0)]:print("D")
    if point==[(0,0),(1,0),(1,1),(2,1)]:print("E")
    if point==[(0,0),(0,1),(1,1),(1,2)]:print("F")
    if point==[(0,0),(1,-1),(1,0),(2,-1)]:print("G")
while True:
    try:
        N=[input() for _ in range(8)]
        points(trim(N))
    except:break

Python: def get_input():
    while True:
        try:
            yield ''.join(input())
        except EOFError:
            break

N = list(get_input())
board = [[0 for i in range(11)] for j in range(11)]

for l in range(0, len(N), 9):
    for i in range(l, l+8):
        for j in range(len(N[i])):
            board[i-l][j] = int(N[i][j])
    ans = "X"
    for i in range(8):
        for j in range(8):
            if board[i][j] == 1:
                if board[i+1][j] == 1 and board[i][j+1] == 1 and board[i+1][j+1] == 1:
                    ans = "A"
                elif board[i+1][j] == 1 and board[i+2][j] == 1:
                    ans = "B"
                elif board[i][j+1] == 1 and board[i][j+2] == 1:
                    ans = "C"
                elif board[i][j+1] == 1 and board[i+1][j+1] == 1:
                    ans = "E"
                elif board[i+1][j] == 1 and board[i+1][j+1] == 1:
                    ans = "F"
                elif board[i][j+1] == 1:
                    ans = "G"
                else:
                    ans = "D"
                break
        if ans != "X":
            break
    print(ans)

Python: import sys

for s in sys.stdin:
	sur = [list(map(int, s.strip()))]
	if 1 not in sur[0]:
		sur.pop()
	for _ in range(7):
		sur.append(list(map(int, input().strip())))
		if 1 not in sur[-1]:
			sur.pop()

	if len(sur) == 1:
		print("C")
	elif len(sur) == 2:
		if sur[0].index(1) == sur[1].index(1):
			print("A")
		elif sur[0].index(1) < sur[1].index(1):
			print("E")
		else:
			print("G")
	elif len(sur) == 3:
		if sur[0].index(1) > sur[2].index(1):
			print("D")
		else:
			print("F")
	elif len(sur) == 4:
		print("B")

Python: while True:
    try:
        Map = []
        Base = []
        End = []
        for i in range(8):
            Map.append(list(map(str,input())))
        for i in range(8):
            if Base == []:
                
                for j in range(8):
                    if Map[i][j] == '1':
                        Base = [j,i]
                        break
            else:
                break
        for i in range(7,-1,-1):
            if End == []:
                for j in range(7,-1,-1):
                    if Map[i][j] == '1':
                        End = [j,i]
                        break
            else:
                break
        Yoko = End[0] - Base[0]
        Tate = End[1] - Base[1]
        if Tate == 1 and Yoko == 1:
            print("A")
        elif Yoko == 0 and Tate == 3:
            print("B")
        elif Tate == 0 and Yoko == 3:
            print("C")
        elif Yoko == -1 and Tate == 2:
            print("D")
        elif Yoko == 2 and Tate == 1:
            print("E")
        elif Yoko == 1 and Tate == 2:
            print("F")
        elif Tate == 1 and Yoko == 0:
            print("G")
        kara = input()
            
    except EOFError:
        break

Python: import sys

for s in sys.stdin:
	sur = [list(map(int, s.strip()))]
	if 1 not in sur[0]:
		sur.pop()
	for _ in range(7):
		sur.append(list(map(int, input().strip())))
		if 1 not in sur[-1]:
			sur.pop()

	if len(sur) == 1:
		print("C")
	elif len(sur) == 2:
		if sur[0].index(1) == sur[1].index(1):
			print("A")
		elif sur[0].index(1) < sur[1].index(1):
			print("E")
		else:
			print("G")
	elif len(sur) == 3:
		if sur[0].index(1) > sur[2].index(1):
			print("D")
		else:
			print("F")
	elif len(sur) == 4:
		print("B")