Language: C++

using System;
using System.Linq;
using System.Collections.Generic;
using static System.Console;
using System.Text;


namespace AtCoder_Beginner_Contest_132
{
    class Program
    {
        static public long[] Sarray() { return ReadLine().Split().Select(long.Parse).ToArray(); }
        static public List<long> Slist() { return ReadLine().Split().Select(long.Parse).ToList(); }
        static void Main(string[] args)
        {
            var ND=Sarray();
            var N = ND[0];
            var D = ND[1];
            var Xij = new List<long>[N];
            for(var i=0;i<N;++i)
            {
                Xij[i] = Slist();
            }
            var cnt = 0;
            for(var i=0;i<N;++i)
            {
                for(var j=i+1;j<N;++j)
                {
                    var sum = 0L;
                    for (var k = 0; k < D;++k)
                    {
                        sum += (long)Math.Pow(Xij[i][k] - Xij[j][k], 2);
                    }
                    if (Math.Sqrt(sum) - (long)Math.Sqrt(sum) < 0.000001)
                        ++cnt;
                }
            }
            WriteLine(cnt);
        }
    }
}

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.Linq;
      |       ^~~~~~
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 'static'
    4 | using static System.Console;
      |       ^~~~~~
a.cc:5:7: error: expected nested-name-specifier before 'System'
    5 | using System.Text;
      |       ^~~~~~
a.cc:12:16: error: expected unqualified-id before 'public'
   12 |         static public long[] Sarray() { return ReadLine().Split().Select(long.Parse).ToArray(); }
      |                ^~~~~~
a.cc:13:16: error: expected unqualified-id before 'public'
   13 |         static public List<long> Slist() { return ReadLine().Split().Select(long.Parse).ToList(); }
      |                ^~~~~~
a.cc:14:26: error: 'string' has not been declared
   14 |         static void Main(string[] args)
      |                          ^~~~~~
a.cc:14:35: error: expected ',' or '...' before 'args'
   14 |         static void Main(string[] args)
      |                                   ^~~~
a.cc:40:6: error: expected ';' after class definition
   40 |     }
      |      ^
      |      ;
a.cc: In static member function 'static void AtCoder_Beginner_Contest_132::Program::Main(int*)':
a.cc:16:13: error: 'var' was not declared in this scope
   16 |             var ND=Sarray();
      |             ^~~
a.cc:17:17: error: expected ';' before 'N'
   17 |             var N = ND[0];
      |                 ^
a.cc:18:17: error: expected ';' before 'D'
   18 |             var D = ND[1];
      |                 ^
a.cc:19:17: error: expected ';' before 'Xij'
   19 |             var Xij = new List<long>[N];
      |                 ^~~
a.cc:20:21: error: expected ';' before 'i'
   20 |             for(var i=0;i<N;++i)
      |                     ^
a.cc:20:25: error: 'i' was not declared in this scope
   20 |             for(var i=0;i<N;++i)
      |                         ^
a.cc:20:27: error: 'N' was not declared in this scope
   20 |             for(var i=0;i<N;++i)
      |                           ^
a.cc:22:17: error: 'Xij' was not declared in this scope
   22 |                 Xij[i] = Slist();
      |                 ^~~
a.cc:22:26: error: 'Slist' was not declared in this scope
   22 |                 Xij[i] = Slist();
      |                          ^~~~~
a.cc:24:17: error: expected ';' before 'cnt'
   24 |             var cnt = 0;
      |                 ^~~
a.cc:25:21: error: expected ';' before 'i'
   25 |             for(var i=0;i<N;++i)
      |                     ^
a.cc:25:25: error: 'i' was not declared in this scope
   25 |             for(var i=0;i<N;++i)
      |                         ^
a.cc:25:27: error: 'N' was not declared in this scope
   25 |             for(var i=0;i<N;++i)
      |                           ^
a.cc:27:25: error: expected ';' before 'j'
   27 |                 for(var j=i+1;j<N;++j)
      |                         ^
a.cc:27:31: error: 'j' was not declared in this scope
   27 |                 for(var j=i+1;j<N;++j)
      |                               ^
a.cc:29:25: error: expected ';' before 'sum'
   29 |                     var sum = 0L;
      |                         ^~~
a.cc:30:30: error: expected ';' before 'k'
   30 |                     for (var k = 0; k < D;++k)
      |                              ^
a.cc:30:37: error: 'k' was not declared in this scope
   30 |                     for (var k = 0; k < D;++k)
      |                                     ^
a.cc:30:41: error: 'D' was not declared in this scope
   30 |                     for (var k = 0; k < D;++k)
      |                                         ^
a.cc:32:25: error: 'sum' was not declared in this scope
   32 |                         sum += (long)Math.Pow(Xij[i][k] - Xij[j][k], 2);
      |                         ^~~
a.cc:32:38: error: 'Math' was not declared in this scope
   32 |                         sum += (long)Math.Pow(Xij[i][k] - Xij[j][k], 2);
      |                                      ^~~~
a.cc:32:47: error: 'Xij' was not declared in this scope
   32 |                         sum += (long)Math.Pow(Xij[i][k] - Xij[j][k], 2);
      |                                               ^~~
a.cc:34:25: error: 'Math' was not declared in this scope
   34 |                     if (Math.Sqrt(sum) - (long)Math.Sqrt(sum) < 0.000001)
      |                         ^~~~
a.cc:34:35: error: 'sum' was not declared in this scope
   34 |                     if (Math.Sqrt(sum) - (long)Math.Sqrt(sum) < 0.000001)
      |                                   ^~~
a.cc:35:27: error: 'cnt' was not declared in this scope; did you mean 'int'?
   35 |                         ++cnt;
      |                           ^~~
      |                           int
a.cc:38:23: error: 'cnt' was not declared in this scope; did you mean 'int'?
   38 |             WriteLine(cnt);
      |                       ^~~
      |                       int
a.cc:38:13: error: 'WriteLine' was not declared in this scope
   38 |             WriteLine(cnt);
      |             ^~~~~~~~~