Language: C++

using System;

class Program
{
   static int Main()
    {
        string[] in1 = Console.ReadLine().Split(' '),in2;
        int n = int.Parse(in1[0]), q = int.Parse(in1[1]),l,r;
        int[] ac = new int[n];
        string s = Console.ReadLine();
        for (var i = 1; i < n; i++)
        {
            if (s[i - 1] == 'A' && s[i] == 'C')
            {
                ac[i] = ac[i - 1] + 1;
            }
            else {
                ac[i] = ac[i - 1];
            }
        }
        for (var i = 0; i < q; i++)
        {
            in2 = Console.ReadLine().Split(' ');
            l = int.Parse(in2[0])-1;
            r = int.Parse(in2[1])-1;
            Console.WriteLine((ac[r] - ac[l]).ToString("d"));
        }
        return 0;
    }
}

Compiler output:
a.cc:1:7: error: expected nested-name-specifier before 'System'
    1 | using System;
      |       ^~~~~~
a.cc:30:2: error: expected ';' after class definition
   30 | }
      |  ^
      |  ;
a.cc: In static member function 'static int Program::Main()':
a.cc:7:9: error: 'string' was not declared in this scope
    7 |         string[] in1 = Console.ReadLine().Split(' '),in2;
      |         ^~~~~~
a.cc:7:16: error: expected primary-expression before ']' token
    7 |         string[] in1 = Console.ReadLine().Split(' '),in2;
      |                ^
a.cc:8:17: error: expected primary-expression before 'int'
    8 |         int n = int.Parse(in1[0]), q = int.Parse(in1[1]),l,r;
      |                 ^~~
a.cc:9:12: error: structured binding declaration cannot have type 'int'
    9 |         int[] ac = new int[n];
      |            ^~
a.cc:9:12: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:9:12: error: empty structured binding declaration
a.cc:9:15: error: expected initializer before 'ac'
    9 |         int[] ac = new int[n];
      |               ^~
a.cc:10:16: error: expected ';' before 's'
   10 |         string s = Console.ReadLine();
      |                ^
a.cc:11:14: error: 'var' was not declared in this scope
   11 |         for (var i = 1; i < n; i++)
      |              ^~~
a.cc:11:25: error: 'i' was not declared in this scope
   11 |         for (var i = 1; i < n; i++)
      |                         ^
a.cc:13:17: error: 's' was not declared in this scope
   13 |             if (s[i - 1] == 'A' && s[i] == 'C')
      |                 ^
a.cc:15:17: error: 'ac' was not declared in this scope
   15 |                 ac[i] = ac[i - 1] + 1;
      |                 ^~
a.cc:18:17: error: 'ac' was not declared in this scope
   18 |                 ac[i] = ac[i - 1];
      |                 ^~
a.cc:21:14: error: 'var' was not declared in this scope
   21 |         for (var i = 0; i < q; i++)
      |              ^~~
a.cc:21:25: error: 'i' was not declared in this scope
   21 |         for (var i = 0; i < q; i++)
      |                         ^
a.cc:21:29: error: 'q' was not declared in this scope
   21 |         for (var i = 0; i < q; i++)
      |                             ^
a.cc:23:13: error: 'in2' was not declared in this scope; did you mean 'int'?
   23 |             in2 = Console.ReadLine().Split(' ');
      |             ^~~
      |             int
a.cc:23:19: error: 'Console' was not declared in this scope
   23 |             in2 = Console.ReadLine().Split(' ');
      |                   ^~~~~~~
a.cc:24:13: error: 'l' was not declared in this scope
   24 |             l = int.Parse(in2[0])-1;
      |             ^
a.cc:24:17: error: expected primary-expression before 'int'
   24 |             l = int.Parse(in2[0])-1;
      |                 ^~~
a.cc:25:13: error: 'r' was not declared in this scope
   25 |             r = int.Parse(in2[1])-1;
      |             ^
a.cc:25:17: error: expected primary-expression before 'int'
   25 |             r = int.Parse(in2[1])-1;
      |                 ^~~
a.cc:26:32: error: 'ac' was not declared in this scope
   26 |             Console.WriteLine((ac[r] - ac[l]).ToString("d"));
      |                                ^~