Language: C++

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

namespace Test01
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            //a[i] = i番目の箱の余り 0 or 1
            int[] a = new int[N + 1];
            string[] input = Console.ReadLine().Split(' ');
            for (int i = 1; i <= N; i++) a[i] = int.Parse(input[i - 1]);

            //b[i] := i番目の箱にボールが何個入っているか
            int[] b = new int[N + 1];

            //bについてN-1番目から0番目を決めていく
            for(int i = N; i >= 1; i--)
            {
                int sum = 0;
                for(int j = i; j <= N; j += i)
                {
                    sum += b[j];
                }
                if (a[i] != sum % 2) b[i] = 1;
            }
           
            //ボールの入っている箱に書いてある番号を入れる
            List<int> ans_list = new List<int>();

            for(int i = 1; i <= N; i++)
            {
                if (b[i] == 1) ans_list.Add(i);
            }

            Console.WriteLine(ans_list.Count());
            if(ans_list.Count() != 0)Console.WriteLine(string.Join(" ", ans_list));
        }
    }
}


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.Generic;
      |       ^~~~~~
a.cc:3:7: error: expected nested-name-specifier before 'System'
    3 | using System.Linq;
      |       ^~~~~~
a.cc:4:7: error: expected nested-name-specifier before 'System'
    4 | using System.Text;
      |       ^~~~~~
a.cc:5:7: error: expected nested-name-specifier before 'System'
    5 | using System.Threading.Tasks;
      |       ^~~~~~
a.cc:11:26: error: 'string' has not been declared
   11 |         static void Main(string[] args)
      |                          ^~~~~~
a.cc:11:35: error: expected ',' or '...' before 'args'
   11 |         static void Main(string[] args)
      |                                   ^~~~
a.cc:44:6: error: expected ';' after class definition
   44 |     }
      |      ^
      |      ;
a.cc: In static member function 'static void Test01::Program::Main(int*)':
a.cc:13:21: error: expected primary-expression before 'int'
   13 |             int N = int.Parse(Console.ReadLine());
      |                     ^~~
a.cc:15:16: error: structured binding declaration cannot have type 'int'
   15 |             int[] a = new int[N + 1];
      |                ^~
a.cc:15:16: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:15:16: error: empty structured binding declaration
a.cc:15:19: error: expected initializer before 'a'
   15 |             int[] a = new int[N + 1];
      |                   ^
a.cc:16:13: error: 'string' was not declared in this scope
   16 |             string[] input = Console.ReadLine().Split(' ');
      |             ^~~~~~
a.cc:16:20: error: expected primary-expression before ']' token
   16 |             string[] input = Console.ReadLine().Split(' ');
      |                    ^
a.cc:17:42: error: 'a' was not declared in this scope
   17 |             for (int i = 1; i <= N; i++) a[i] = int.Parse(input[i - 1]);
      |                                          ^
a.cc:17:49: error: expected primary-expression before 'int'
   17 |             for (int i = 1; i <= N; i++) a[i] = int.Parse(input[i - 1]);
      |                                                 ^~~
a.cc:20:16: error: structured binding declaration cannot have type 'int'
   20 |             int[] b = new int[N + 1];
      |                ^~
a.cc:20:16: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:20:16: error: empty structured binding declaration
a.cc:20:19: error: expected initializer before 'b'
   20 |             int[] b = new int[N + 1];
      |                   ^
a.cc:28:28: error: 'b' was not declared in this scope
   28 |                     sum += b[j];
      |                            ^
a.cc:30:21: error: 'a' was not declared in this scope
   30 |                 if (a[i] != sum % 2) b[i] = 1;
      |                     ^
a.cc:30:38: error: 'b' was not declared in this scope
   30 |                 if (a[i] != sum % 2) b[i] = 1;
      |                                      ^
a.cc:34:13: error: 'List' was not declared in this scope
   34 |             List<int> ans_list = new List<int>();
      |             ^~~~
a.cc:34:18: error: expected primary-expression before 'int'
   34 |             List<int> ans_list = new List<int>();
      |                  ^~~
a.cc:38:21: error: 'b' was not declared in this scope
   38 |                 if (b[i] == 1) ans_list.Add(i);
      |                     ^
a.cc:38:32: error: 'ans_list' was not declared in this scope
   38 |                 if (b[i] == 1) ans_list.Add(i);
      |                                ^~~~~~~~
a.cc:41:13: error: 'Console' was not declared in this scope
   41 |             Console.WriteLine(ans_list.Count());
      |             ^~~~~~~
a.cc:41:31: error: 'ans_list' was not declared in this scope
   41 |             Console.WriteLine(ans_list.Count());
      |                               ^~~~~~~~