Language: C++

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Numerics;

class Program
{
    const int MOD = 1000000007;
    static void Main(string[] args)
    {
        new Program().Solve();
    }

    void Solve()
    {
        Scanner cin = new Scanner();
        string s = cin.Next();

        bool isDifficult = false;
        char prev = 'a';
        foreach(var c in s)
        {
            if (prev == c)
            {
                isDifficult = true;
            }
            prev = c;
        }

        var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
        Console.SetOut(sw);

        if (isDifficult)
        {
            Console.WriteLine("Bad");
        }
        else
        {
            Console.WriteLine("Good");

        }

        Console.Out.Flush();
        
    }
}


class Scanner
{
    string[] s;
    int i;

    char[] cs = new char[] { ' ' };

    public Scanner()
    {
        s = new string[0];
        i = 0;
    }

    public string Next()
    {
        if (i < s.Length) return s[i++];
        string st = Console.ReadLine();
        while (st == "") st = Console.ReadLine();
        s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
        if (s.Length == 0) return Next();
        i = 0;
        return s[i++];
    }

    public int NextInt()
    {
        return int.Parse(Next());
    }

    public char[] ArrayChar()
    {
        return Next().ToCharArray();
    }
    public int[] ArrayInt(int N, int add = 0)
    {
        int[] Array = new int[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = NextInt() + add;
        }
        return Array;
    }

    public long NextLong()
    {
        return long.Parse(Next());
    }

    public long[] ArrayLong(int N, long add = 0)
    {
        long[] Array = new long[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = NextLong() + add;
        }
        return Array;
    }

    public double NextDouble()
    {
        return double.Parse(Next());
    }


    public double[] ArrayDouble(int N, double add = 0)
    {
        double[] Array = new double[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = NextDouble() + add;
        }
        return Array;
    }
}

Compiler output:
a.cc:1:7: error: expected nested-name-specifier before 'System'
    1 | using System;
      |       ^~~~~~
a.cc:2:7: error: expected nested-name-specifier before 'System'
    2 | using System.Collections;
      |       ^~~~~~
a.cc:3:7: error: expected nested-name-specifier before 'System'
    3 | using System.Collections.Generic;
      |       ^~~~~~
a.cc:4:7: error: expected nested-name-specifier before 'System'
    4 | using System.Linq;
      |       ^~~~~~
a.cc:5:7: error: expected nested-name-specifier before 'System'
    5 | using System.Text;
      |       ^~~~~~
a.cc:6:7: error: expected nested-name-specifier before 'System'
    6 | using System.Threading.Tasks;
      |       ^~~~~~
a.cc:7:7: error: expected nested-name-specifier before 'System'
    7 | using System.IO;
      |       ^~~~~~
a.cc:8:7: error: expected nested-name-specifier before 'System'
    8 | using System.Numerics;
      |       ^~~~~~
a.cc:13:22: error: 'string' has not been declared
   13 |     static void Main(string[] args)
      |                      ^~~~~~
a.cc:13:31: error: expected ',' or '...' before 'args'
   13 |     static void Main(string[] args)
      |                               ^~~~
a.cc:50:2: error: expected ';' after class definition
   50 | }
      |  ^
      |  ;
a.cc: In static member function 'static void Program::Main(int*)':
a.cc:15:22: error: expected ';' before '.' token
   15 |         new Program().Solve();
      |                      ^
a.cc: In member function 'void Program::Solve()':
a.cc:20:9: error: 'Scanner' was not declared in this scope
   20 |         Scanner cin = new Scanner();
      |         ^~~~~~~
a.cc:21:9: error: 'string' was not declared in this scope
   21 |         string s = cin.Next();
      |         ^~~~~~
a.cc:25:17: error: 'var' was not declared in this scope
   25 |         foreach(var c in s)
      |                 ^~~
a.cc:25:9: error: 'foreach' was not declared in this scope
   25 |         foreach(var c in s)
      |         ^~~~~~~
a.cc:34:13: error: expected ';' before 'sw'
   34 |         var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
      |             ^~
a.cc:35:9: error: 'Console' was not declared in this scope
   35 |         Console.SetOut(sw);
      |         ^~~~~~~
a.cc:35:24: error: 'sw' was not declared in this scope
   35 |         Console.SetOut(sw);
      |                        ^~
a.cc: At global scope:
a.cc:55:5: error: 'string' does not name a type
   55 |     string[] s;
      |     ^~~~~~
a.cc:58:9: error: expected unqualified-id before '[' token
   58 |     char[] cs = new char[] { ' ' };
      |         ^
a.cc:60:11: error: expected ':' before 'Scanner'
   60 |     public Scanner()
      |           ^~~~~~~~
      |           :
a.cc:66:11: error: expected ':' before 'string'
   66 |     public string Next()
      |           ^~~~~~~
      |           :
a.cc:66:12: error: 'string' does not name a type
   66 |     public string Next()
      |            ^~~~~~
a.cc:77:11: error: expected ':' before 'int'
   77 |     public int NextInt()
      |           ^~~~
      |           :
a.cc:82:11: error: expected ':' before 'char'
   82 |     public char[] ArrayChar()
      |           ^~~~~
      |           :
a.cc:82:16: error: expected unqualified-id before '[' token
   82 |     public char[] ArrayChar()
      |                ^
a.cc:86:11: error: expected ':' before 'int'
   86 |     public int[] ArrayInt(int N, int add = 0)
      |           ^~~~
      |           :
a.cc:86:15: error: expected unqualified-id before '[' token
   86 |     public int[] ArrayInt(int N, int add = 0)
      |               ^
a.cc:96:11: error: expected ':' before 'long'
   96 |     public long NextLong()
      |           ^~~~~
      |           :
a.cc:101:11: error: expected ':' before 'long'
  101 |     public long[] ArrayLong(int N, long add = 0)
      |           ^~~~~
      |           :
a.cc:101:16: error: expected unqualified-id before '[' token
  101 |     public long[] ArrayLong(int N, long add = 0)
      |                ^
a.cc:111:11: error: expected ':' before 'double'
  111 |     public double NextDouble()
      |           ^~~~~~~
      |           :
a.cc:117:11: error: expected ':' before 'double'
  117 |     public double[] ArrayDouble(int N, double add = 0)
      |           ^~~~~~~
      |           :
a.cc:117:18: error: expected unqualified-id before '[' token
  117 |     public double[] ArrayDouble(int N, double add = 0)
      |                  ^
a.cc:126:2: error: expected ';' after class definition
  126 | }
      |  ^
      |  ;
a.cc: In constructor 'Scanner::Scanner()':
a.cc:62:9: error: 's' was not declared in this scope
   62 |         s = new string[0];
      |         ^
a.cc:62:17: error: 'string' does not name a type
   62 |         s = new string[0];
      |                 ^~~~~~
a.cc: In member function 'int Scanner::NextInt()':
a.cc:79:16: error: expected primary-expression before 'int'
   79 |         return int.Parse(Next());
      |                ^~~
a.cc:79:16: error: expected ';' before 'int'
a.cc:79:19: error: expected unqualified-id before '.' token
   79 |         return int.Parse(Next());
      |                   ^
a.cc: In member function 'long int Scanner::NextLong()':
a.cc:98:16: error: expected primary-expression before 'long'
   98 |         return long.Parse(Next());
      |                ^~~~
a.cc:98:16: error: expected ';' before 'long'
a.cc:98:20: error: expected unqualified-id before '.' token
   98 |         return long.Parse(Next());
      |                    ^
a.cc: In member function 'double Scanner::NextDouble()':
a.cc:113:16: error: expected primary-expression before 'double'
  113 |         return double.Parse(Next());
      |                ^~~~~~
a.cc:113:16: error: expected ';' before 'double'
a.cc:113:22: error: expected unqualified-id before '.' token
  113 |         return double.Parse(Next());
      |                      ^