Go: package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	var scanner = bufio.NewScanner(os.Stdin)
	board := make([][]int, 8)
	for i := range board {
		board[i] = make([]int, 8)
			for j := range board[i] {
				board[i][j] = 0
			}
	}
	var ans string
	for scanner.Scan() {
		tmp := strings.Split(scanner.Text(), "")
		for i := 0; i < 8; i++ {
			board[0][i], _ = strconv.Atoi(tmp[i])
		}
		for i := 1; i < 8; i++ {
			scanner.Scan()
			row := strings.Split(scanner.Text(), "")
			for j := 0; j < 8; j++ {
				board[i][j], _ = strconv.Atoi(row[j])
			}
		}
		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 <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <utility>
#include <stack>
#include <functional>
#include <queue>
#include <cmath>

#define rep(i,j,k) for(int i=j;i<k;i++)
#define drep(n,m) for(int i=0;i<n;i++)for(int j=0;j<m;j++)
#define Sort(x) sort((x).begin(),(x).end())
#define fi first
#define se second
#define vi vector<int>
#define INF 1000000000
#define MOD 1000000009
#define pb push_back
#define mp make_pair
typedef long long ll;
int dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};

using namespace std;

ll gcd(ll a,ll b){
    if(a<b){
        int t=a;a=b;b=t;
    }
    int c=a%b;
    while(c!=0){
        a=b;
        b=c;
        c=a%b;
    }
    return b;
}

ll lcm(ll a,ll b){
    return a*b/gcd(a,b);
}

bool isPrime(int x){
    if(x==1)return false;
    if(x==2)return true;
    if(x%2==0)return false;
    for(int i=3;i<=sqrt(x);i+=2){
        if(x%i==0)return false;
    }
    return true;
}

int kaizyo(int x){
    if(x==1)return x;
    else return x*kaizyo(x-1);
}


int main() {
    vector<vector<char>> v(8,vector<char>(8));
    while(cin>>v[0][0]){
        rep(i,1,8)cin>>v[0][i];
    rep(i,1,8)rep(j,0,8)cin>>v[i][j];
    rep(i,0,8){
        rep(j,0,8){
            if(v[i][j]=='1'){
                //cout<<9<<endl;
                if(v[i][j+1]=='1'&&v[i+1][j]=='1'&&v[i+1][j+1]=='1'){cout<<"A"<<endl;goto AWAY;}
                if(v[i+1][j]=='1'&&v[i+1][j-1]=='1'&&v[i+2][j-1]=='1'){cout<<"D"<<endl;goto AWAY;}
                if(v[i][j+1]=='1'&&v[i+1][j+2]=='1'&&v[i+1][j+1]=='1'){cout<<"E"<<endl;goto AWAY;}
                if(v[i][j+1]=='1'&&v[i+2][j+1]=='1'&&v[i+1][j+1]=='1'){cout<<"F"<<endl;goto AWAY;}
                if(v[i][j+1]=='1'&&v[i+1][j]=='1'&&v[i+1][j-1]=='1'){cout<<"G"<<endl;goto AWAY;}
                if(v[i+3][j]=='1'){cout<<"B"<<endl;goto AWAY;}
                if(v[i][j+3]=='1'){cout<<"C"<<endl;goto AWAY;}
            }
        }
    }
    AWAY:;
    }
    return 0;
}

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

#define REP(i,n,m) for(int i=n;i<m;i++)
#define rep(i,n) REP(i,0,n)

char t[10][10];
int w = 8;
int h = 8;

int dx[][4] = {
  {0,1,0,1},
  {0,0,0,0},
  {0,1,2,3},
  {0,-1,0,-1},
  {0,1,1,2},
  {0,0,1,1},
  {0,1,-1,0},
};
int dy[][4] = {
  {0,0,1,1},
  {0,1,2,3},
  {0,0,0,0},
  {0,1,1,2},
  {0,0,1,1},
  {0,1,1,2},
  {0,0,1,1},
};

int check(int y,int x,int kind){
  for(int i=0;i<4;i++){
    int nx = x + dx[kind][i];
    int ny = y + dy[kind][i];
    if(nx>=0 && nx<w && ny>=0 && ny<h){
        if(t[ny][nx] != '1'){
          return false;
        }
    }
  }
    return true;
}

void solve(){
  rep(i,h){
    rep(j,w){
      rep(k,7){
        int tmp = check(i,j,k);
        if(tmp){
          cout<<(char)('A'+k)<<endl;
          return;
        }
      }
    }
  }
}

int main(){
  while(1){
    rep(i,h){
      if(!(cin>>t[i])) return 0;
    }
    solve();
  }
}

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

int main(){
    char mat[8][9]={0};
    
    while(cin >> mat[0]){
        char ans;
        
        for(int i = 1; i < 8 ; i++) cin >> mat[i];
        
        for(int i = 0 ; i < 8 ; i++)
            for(int j = 0 ; j < 8 ; j++)
                mat[i][j] -= '0';
        
        for(int i = 0 ;  ; i++){
            for(int j = 0 ; j < 8 ; j++){
                if(mat[i][j] == 1){
                    if(mat[i][j+3]) ans = 'C';
                    else if(mat[i+3][j]) ans = 'B';
                    else if(mat[i][j+1]&&mat[i+1][j]&&mat[i+1][j+1]) ans = 'A';
                    else if(mat[i+1][j-1]&&mat[i+2][j-1]) ans = 'D';
                    else if(mat[i][j+1]&&mat[i+1][j+2]) ans = 'E';
                    else if(mat[i+1][j]&&mat[i+2][j+1]) ans = 'F';
                    else ans = 'G';
                    
                    goto end;
                }
                
            }
        }
        end:
        cout << ans << endl;
        
        }

    
    return 0;
}

C++: #include<iostream>
#include<string.h>
#include<vector>
#include<list>
#include<stdio.h>
#include<math.h>
#include<iomanip>
#include<map>
#include<stack>
#include<queue>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define debug(x) cout << "debug " << x << endl;
using namespace std;

int main(){
    enum blocks{
        A = 18, B = 48, C = 6, D = 30, E = 20, F = 34, G = 16
    };
    string surface, input;
    while(cin >> input){
        surface = input;
        rep(i,7){
            cin >> input;
            surface+= input;
        }
        int first = 0, location = 0;
        rep(i,65){
            if(surface[i] == '1' && first == 0){
                first = i;
            }else if(surface[i] == '1'){
                location+= i - first;
            }
        }
        if(A == location) cout << 'A' << endl;
        else if(B == location) cout << 'B' << endl;
        else if(C == location) cout << 'C' << endl;
        else if(D == location) cout << 'D' << endl;
        else if(E == location) cout << 'E' << endl;
        else if(F == location) cout << 'F' << endl;
        else if(G == location) cout << 'G' << endl;
    }
}

C++: #include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
int main(){
    char field[65];
    char a[7][26]={
        "1100000011",
        "1000000010000000100000001",
        "1111",
        "1000000110000001",
        "11000000011",
        "100000001100000001",
        "110000011"
    };
    while(cin>>field){
        for(int i=1;i<8;i++)scanf("%s",field+i*8);
        char *pnt;
        pnt=strchr(field,'1');
        for(int i=0;i<7;i++){
            if(!strncmp(pnt,a[i],strlen(a[i]))){
                char x='A'+i;
                cout<<x<<endl;
                break;
            }
        }
    }
    return 0;
}